Electroplating Industry Terminology for Designers
Common Noun
This standard includes terms and explanations commonly used in electroplating and applies to electroplating and electroplating-related processes.
- Chemical corrosion–chemical corrosion
The corrosion (oxidation) process of metals under non-electrochemical action. Usually refers to corrosion caused by pure chemical action in non-electrolyte solutions and dry gases.
- Electric double-layer–electric double layer
Charge layers of equal size and opposite signs exist on the interface between the electrode and the electrolyte solution.
- Bipolar electrode–bipolar electrode
A conductor that is not connected to an external power source is immersed in the electrolyte between the anode and the cathode. The part of the conductor near the anode acts as the cathode, and the part near the cathode acts as the anode.
- Dispersion ability–throwing power Throwing power
The ability of a given solution to make the distribution of the coating on an electrode (usually the cathode) more uniform than that obtained with the primary current distribution, under certain conditions.
This term can also be used for anodic processes, with a definition similar to that described above.
- Decomposition voltage –decomposition voltage
Its definition is similar to the above.
The minimum voltage at which an electrochemical reaction can continue at an appreciable rate (the ohmic voltage drop of the solution is not included).
- Insoluble anode (inert anode)–inert anode / insoluble anode
An anode where no anodic dissolution reaction occurs when current is passed.
- Electrochemistry–electrochemistry
The science of studying the properties of the contact interface of electronic and ionic conductors and their changes.
- Electrochemical polarization (activation polarization)–activation polarization
Polarization due to difficulties encountered in the progress of the electrochemical reaction.
- Electrochemical corrosion–electrochemical corrosion
The metal corrosion (oxidation) process obeys the laws of an electrochemical reaction in the electrolyte solution or the liquid film on the metal surface
- Electrochemical equivalent –electrochemical equivalent
The theoretical weight of the product is formed by the electrode reaction through a unit of electricity (eg, 1 amp-hour, 1 coulomb, or 1-farad hour) on the electrode. Usually expressed in grams per coulomb or grams per ampere-hour.
11 Conductivity (specific conductance)–conductivity
The conductance of a conductor per unit cross-sectional area and unit length is usually expressed in S/m.
12 Electrophoresis–electrophoresis cataphoresis
The migration phenomenon of charged colloidal particles in liquid medium relative to liquid under the action of an external electric field.
13 Electromotive force–electromotive force
The potential difference between the electrodes of a galvanic cell when it is open-circuited.
14 Passivation potential –passivation potential
Potential at which the dissolution rate of the metal anode suddenly decreases when the metal electrode is anodically polarized. Usually, the corrosion current experiences a maximum value before reaching the passivation potential.
15 Corrosion potential –corrosion potential
The stable electrode potential is established spontaneously by metal materials in a specific corrosive environment.
16 Current density –current density
The current intensity passing through the electrode per unit area is usually expressed in A/dm2.
17 Current efficiency –current efficiency
When a unit of electricity passes through the electrode, the ratio of the actual mass of the electrode reaction product to the electrochemical equivalent is usually expressed in %.
18 Corrosion rate, corrosion current –corrosion rate(vcor), corrosion current(Icor)
The corrosion rate is the amount of species transformation per unit time on a particular surface of a material. Or by Faraday’s Law, the corrosion rate is the current at the corrosion potential.
The corrosion current is: Icor = nFvcor;
In the formula: the number of electrons in the n-electrode reaction;
F – Faraday’s constant;
vector – Corrosion rate.
19 electrode –electrode
A conductor is placed in a conducting medium such as an electrolyte, melt, solid, or gas. Current flows into or out of a conductive medium through it.
20 Electrode potential –electrode potential
In a standard state, an electrode and a standard hydrogen electrode (as a negative electrode) form a primary battery, and the measured electromotive force is called the hydrogen standard electrode potential of the electrode, or electrode potential for short. The hydrogen standard electrode potential of various electrodes can indicate the relative magnitude of the potential difference between the electrode and the solution interface.
21 Electrolyte –electrolyte
A substance that has ionic conductivity itself or can exhibit ionic conductivity under certain conditions (such as melting at high temperature or dissolving in a solvent to form a solution).
22 Electrolyte–electrolytic solution
solution with ionic conductivity.
23 ionization degree–the degree of ionization
The ratio of the number of moles of electrolyte present as free ions in a solution to its total number of moles. Usually expressed in %.
24 Depolarization –depolarization
The phenomenon of reducing electrode polarization by adding a depolarizer to an electrolyte solution or electrode.
25 Equilibrium electrode potential –equilibrium electrode potential
The electrode potential at which the electrode reaction is in thermodynamic equilibrium.
26 positive electrode–positive electrode
The electrode with the more positive potential among the two electrodes of the galvanic cell.
27 Negative electrode–negative electrode
The electrode with the more negative potential than the two electrodes of the galvanic cell.
28 cathode –cathode
The electrode where the reduction reaction takes place, is the electrode on which the reactants gain electrons.
29 Cathodic polarization–cathodic polarization
When a current passes through, the electrode potential of the cathode shifts to the negative direction.
30 Cathodic coating–cathodic coating
A metal coating that is more positive than the electrode potential of the base metal.
31 Anode –anode
The electrode where the oxidation reaction occurs, that is, the electrode that can accept the electrons given by the reactant.
32 Anode slime–anode slime
Under the action of electric current, the insoluble residue is produced during the anodic dissolution process.
33 anodic polarization –anodic polarization
When a current flows, the electrode potential of the anode shifts to the positive direction.
34 Anodized coating –anodic coating
A metal coating with a more negative electrode potential than the base metal.
35 Migration number –transport number
When a current passes through an electrolyte solution, the ratio of the current carried by a certain ion in the solution to the total current passing through it is called the migration number of the ion.
36 Overpotential –overpotential
The difference between the electrode potential and the thermodynamic equilibrium electrode potential is when there is current passing through the electrode.
37 Diffusion layer–diffusion layer
There is a thin layer of solution with a concentration gradient near the electrode surface when the current is passed.
38 Stray current –stray current
The current flowing in other circuits (such as the plating bath tank or heater, etc.) other than the line that needs to pass the current.
39 Conducting salt–conducting salt
Salts are added to the electrolyte to increase the conductivity of the solution.
40 Volume current density –volume current density
The intensity of the current passing through a unit volume of electrolyte solution. Usually expressed in A/L.
41 deposition rate –deposition rate
The thickness of the metal deposited on the surface of the plated part per unit time. Usually expressed in μm/h.
42 Primary current distribution –primary current distribution
The current distribution on the electrode surface in the absence of electrode polarization.
43 Local corrosion –local corrosion
Corrosion damage is mainly concentrated in local areas of the surface, while other parts are hardly corroded.
44 Polarization –polarization
When there is current passing through the electrode, the electrode potential deviates from its equilibrium value.
45 Polarizability–polarizability
The rate of change of electrode potential with current density is equivalent to the change of electrode potential caused by changing unit current density.
46 Polarization curve –polarization curve
A curve describing the relationship between electrode potential and current density through the electrode.
47 Interelectrode distance–Interelectrode distance
The distance between two electrodes (positive, negative, or negative, anode) in a primary cell or electrolytic cell.
48 Emulsification–emulsification
The phenomenon in which one liquid is uniformly dispersed in another immiscible liquid as tiny droplets.
49 Stress corrosion–stress corrosion
The cracking phenomenon of metal materials under the combined action of stress and corrosive environment.
50 gassing –gassing
During the electrolysis process, there is obvious gas evolution on the electrode.
51 Activation –activation
The desired behavior is achieved by adjusting the effective ion concentration to eliminate the passivation state of the electrode surface.
52 Activity–activity
In the standard state, the thermodynamic concentration of the components in the solution, that is, the effective concentration used to correct the deviation of the properties of the real solution from the ideal solution.
53 standard electrode potential –standard electrode potential
In the standard state, the activities (or fugacity) of all reactants and products in the electrode reaction are equal to the equilibrium electrode potential of 1.
54 Concentration polarization–concentration polarization
The polarization is caused by changes in the concentration of reactants or products near the electrode surface when current is passed through the electrode.
55 Passivation –passivation
After the metal anode polarization exceeds a certain value in a certain solution, the metal dissolution rate not only does not increase but decreases sharply. This process of changing the metal surface from an “active state” to a “passive state” is called passivation. Passivation caused by anodic polarization is electrochemical passivation, while passivation caused by the action of some passivating agents in solution is called chemical passivation.
56 point corrosion –spot corrosion
Pitting corrosion on metal surfaces.
57 coordination compound –complex compound
Metal ions or atoms and a certain number of negatively charged groups or electrically neutral polar molecules form compounds with coordination bonds.
58 Double salt –double salt
A compound in which two salts are crystallized together in a certain proportion. It is essentially a coordination compound in crystalline form.
59 Hydrogen embrittlement –hydrogen embrittlement
Brittleness is caused by the absorption of hydrogen atoms and the presence of stress in a metal or alloy.
60 Hydrogen penetration –seepage hydrogen
Metal parts often absorb hydrogen atoms in the process of etching, degreasing, or electroplating.
61 Interfacial tension–interracial tension
The force that exists between the two-phase interface to shrink the interface is called interfacial tension. If one of the phases is a gas it is called surface tension.
62 critical current density –critical current density
Within the potential range of the electrode reaction required for electroplating, the highest or lowest current density at which the reaction proceeds can be maintained. Above the highest current density, the potential moves beyond the desired range, and new side reactions will occur. When the current density is lower than the minimum current density, the reaction rate of the electrode decreases and cannot meet the production requirements.
63 Half-cell –half-cell
A system consisting of a single electrode and an electrolyte solution.
64 primary battery –galvanic cell
A device that converts chemical energy directly into electrical energy. A galvanic cell can be seen as consisting of two half-cells.
65 Salt Bridge –salt bridge
A device that connects the two half-cells to reduce the junction potential, usually a glass tube containing a highly concentrated electrolyte solution (eg, a saturated KCL solution).
66 pH–pH value
The negative value of the usual logarithm of the hydrogen ion activity αH+ (or approximately the concentration), that is, pH=-logaH+.
67 Matrix material–basis material(substrate)
A material on which a metal can be deposited or a film can be formed.
68 auxiliary anode –auxiliary anode
Additional anodes are used to improve the current distribution on the surface of the part being plated.
69 auxiliary cathode –auxiliary cathode
Some parts of the workpiece where the current is too concentrated are attached with a cathode of a certain shape to avoid defects such as burrs and scorch. This additional cathode is an auxiliary cathode.
70 Contact potential –contact potential
The potential difference at the interface is when two different conductive materials come into contact.
71 Intergranular corrosion–intercrystalline corrosion
Selective corrosion occurs along grain boundaries.
72 Solubility product –solubility product
The product of the concentrations of the corresponding ions in a saturated solution of a poorly soluble electrolyte at a certain temperature, where the power of each ion concentration is the same as its coefficient in the ionization equation for that electrolyte.
73 Solubility–solubility
At a certain temperature and pressure, the maximum number of grams of solute can be dissolved in 100g of solvent.
74 Micro-covering ability –macro covering power
The ability of metal ions in the plating solution to electrodeposit in pores or scratches under certain conditions.
75 tank voltage –tank voltage
The total potential difference between the two electrodes of the unit cell during electrolysis.
76 Static electrode potential –static electrode potential
The electrode potential of the metal electrode in the electrolyte when no external current flows.
77 chelate–chelate compound
Central ions and ligands
A coordination compound with a cyclic structure formed by multiple coordination.
78 Leveling action –1eveling action
The ability of a bath to make the surface of the coating smoother than the surface of the substrate.
79 Covering ability –covering power
The ability of a bath to deposit metal covering the entire surface of a plated part under specific electroplating conditions.
80 main surface –significant surface
The specified surface before and after electroplating on a part, the coating on the surface is extremely important to the appearance and/or performance of the part.
81 Impulse current –striking current
The instantaneous high current passes through the electroplating process.
Plating Method
1 chemical vapor deposition chemical vapor deposition
A process in which the deposition layer is produced by coagulating a substrate with a heat-induced chemical reaction or vapor-phase reduction.
2 physical vapor deposition
Overlayers of capping layers are typically deposited in a high vacuum by evaporation and subsequent condensation of the element or compound.
3 chemical passivation chemical passivation
The process of treating metal parts with a solution containing an oxidant to form a very thin passive protective film on the surface.
4 chemical oxidation chemical oxidation
The process of forming an oxide film on a metal surface by chemical treatment.
5 Anodizing
The process of electrolysis of metal parts as anodes in a certain electrolyte to form an oxide film with certain functions (such as protection, decoration, or other functions) on the surface.
6 Electroless plating (autocatalytic plating) autocatalytic plating
On the surface of the activated substrate, the metal ions in the plating solution are catalytically reduced to form a metal coating.
7 Laser electroplating 1aser electroplating
Electroplating under the action of a laser.
8 Flash plating flash(flash plate)
Very short energization times produce electroplating of thin layers.
9 Electroplating
The process of using electrolysis to form a uniform, dense and well-bonded metal or alloy deposition layer on the surface of a workpiece.
10 mechanical plating
In the presence of fine metal powder and a suitable chemical agent, the metal surface is hit with a small hard ball to coat the surface with the fine metal powder.
11 immersion plate
A metal deposit resulting from a displacement reaction in which one metal displaces another from solution, such as:
Fe+Cu2+→Cu+Fe2+
12 Electroforming
The process of making or replicating a metal article by electrolytically depositing metal on a casting mold (which can separate the casting mold from the metal deposit).
13 superimposed current electroplating
Electroplating in which pulsed current or alternating current is superimposed on direct current.
14 bright plating
Under suitable conditions, electroplating with a glossy coating is obtained directly from the plating bath.
15 alloy plating alloy plating
The process of co-depositing two or more metals (including non-metal elements) under the action of an electric current.
16 multiplayer plating
Electroplating in which several metal layers with different properties or materials are successively deposited on the same substrate.
17 strike plating
A method of electrodepositing a thin metal layer in a specific solution at a high current density for a short period of time to improve the bonding force between the deposited coating and the substrate.
18 metal electrodeposition metal electrodeposition
The process of reducing metal ions in solution on electrodes and forming a metal phase by means of electrolysis. Including electroplating, electroforming, electrolytic refining, etc.
19 brush plating
A method of selective electroplating using an electrode or brush connected to the anode and capable of supplying the electrolyte required for electroplating, moving over the part acting as the cathode.
20 periodic reverse plating
Electroplating with periodic changes in the current direction.
21 conversion coating conversion coating
A surface film layer containing the metal compound formed by chemical or electrochemical treatment of a metal, such as a chromate film on zinc or cadmium or an oxide film on steel.
22 rack plating
Electroplating using a hanger to hang the part.
23 Composite plating (dispersion plating) composite plating
The process of obtaining a composite coating by simultaneously depositing metal ions and insoluble non-metallic or other metal particles uniformly suspended in a solution by electrochemical or chemical methods.
24 pulse plating
Electroplating with pulse power instead of DC power.
25 Blueing (chemical oxide) of steel
The process of heating steel parts in the air or immersing them in an oxidizing solution to form a usually blue (black) oxide film on the surface.
26 high-speed electrodeposition
In order to obtain high deposition rates, special measures are used to carry out the electroplating process at extremely high cathodic current densities.
27 barrel plating
Parts are electroplated in rotary vessels. Suitable for small parts.
28 plating on plastics
The process of electrodepositing metal coatings on plastic parts.
29 Phosphating
The process of forming an insoluble phosphate protective film on the surface of steel parts.
Test Inspection
1 Atmospheric corrosion test
A test to check the atmospheric corrosion resistance of the coating was carried out according to the specified method in the exposure field of different climatic zones.
2 neutral salt spray test (NSS-test)
The corrosion resistance of the coating is tested by the specified neutral salt spray.
3 Discontinuous water film water break
The phenomenon is that the water film of the workpiece surface is discontinuous due to uneven wettability caused by contamination, which is a method to check the degree of cleaning.
4 pH meter pH meter
An instrument for measuring the pH of a solution.
5 porosity
The number of pinholes per unit area.
6 Internal stress
During the electroplating process, the crystal structure of the coating is changed due to various reasons, so that the coating is stretched or compressed, but because the coating has been fixed on the substrate, the coating is in a state of stress. This internal force acting on the coating is called internal force. stress.
7 conductivity gauge
An instrument for measuring the conductivity of an electrolyte solution.
8 coulomb meter (electricity meter) coulomb meter
An instrument that measures the amount of electricity passing through according to the mass or volume (for gases) of the precipitates on the electrodes during electrolysis.
9 rotating disk electrode
An electrode for measuring the diffusion coefficient and electrochemical parameters of a solution system. It is a metal rod embedded in a concentric plastic cylinder, the bottom surface of the metal rod is the working surface of the electrode, the electrode is connected with the rotating shaft of the rotating motor, and the whole is fixed on a stable frame, the working surface of the electrode is perpendicular to the rotating shaft, and its center is aligned with the rotating shaft. axis. In this way, when the electrode rotates, the liquid phase close to the working surface of the electrode establishes a uniform and stable diffusion layer whose thickness is related to the rotation speed.
10 rotating ring disk electrode
The ring-disk electrode is an electrode equipped with a concentric ring on the working surface of the disk electrode, and the ring and the disk are separated by a thin layer of insulating material. Ring electrodes are used to detect soluble reaction products on disk electrodes, and ring disk electrodes are also commonly used electrodes for electrochemical testing.
11 Pinhole pores
Tiny channels penetrate from the surface of the coating to the bottom of the coating or to the base metal.
12 copper accelerated salt spray (CASS test).
An accelerated corrosion test was conducted with an aqueous solution of sodium chloride containing specified copper salts and acetic acid as a spray.
13 reference electrode reference electrode
Equilibrium electrode potential is a very stable and highly reversible half-cell that can be formed as a galvanic cell with another half-cell to determine the latter’s electrode potential.
14 calomel electrode calomel electrode
A half-cell consisting of mercury, mercurous chloride, and potassium chloride solution of a certain concentration (eg, a saturated solution).
15 Solderability solderability
The ability of a plated surface to be wetted by molten solder.
16 hardness
The ability of a coating to resist being scratched or pressed into its surface by other objects is an important mechanical property of a coating. According to the different measurement methods, different values can be used to express hardness, such as Brinell hardness, Rockwell hardness, Vickers hardness, Shore hardness, and Knoop hardness. Hardness is usually measured with a microhardness tester.
17 Metal discoloration tarnish
Changes in the color of the metal or coating surface due to corrosion, such as darkening, discoloration, etc.
18 dropping corrosion test dropping corrosion test
A test method for testing the corrosion resistance of the protective layer on the surface of the sample by allowing a specific corrosive liquid to be dripped on the surface of the sample in a controlled manner.
19 glass electrode
An electrode that uses a thin glass membrane to separate two solutions to generate a potential difference is often used to measure the pH of a solution.
20 adhesion
A measure of the bond strength between the coating and the substrate is expressed in terms of the force required to separate the coating from the substrate.
21 Haring cell
A rectangular tank made of insulating material, the anode in the tank corresponds to the two cathodes far and near respectively and is used to estimate the dispersion ability of the plating solution and the degree of electrode polarization.
22 potentiostatic method
In order to obtain the relationship between the electrode potential and the current density, the electrode potential of the research electrode can be controlled to change according to a certain law, and the corresponding current density can be measured at the same time.
23 galvanostatic method
In order to obtain the relationship between the current density and the electrode potential, the current density of the research electrode can be controlled to change according to a certain law, and the corresponding electrode potential can be measured at the same time.
24 AC current method a.c method
It is a method to excite the electrode with a small amplitude sine wave alternating current, and from the response of the electrode potential, some parameters of the electrode process can be obtained.
25 Dendritic trees
Rough, loose dendritic, or irregularly raised deposits that form on cathodes (especially edges and other areas of high current density) during electroplating.
26 brittleness
The ability of the coating to withstand the degree of deformation is mainly determined by the coating material and its internal stress.
27 peeling
The phenomenon in which the coating is separated from the substrate in the form of flakes.
28 bubbly blister
A bulge-like defect is caused in the plating layer due to the loss of bonding between the plating layer and the underlying metal.
29 Stripping spalling
Chipping or peeling of the coating surface layer due to some cause (eg uneven thermal expansion or shrinkage).
30 orange peel
A finish that resembles an orange-peel-like appearance.
Pre-plating and Post-plating
1 preplating preplating
In order to expose the real surface of the workpiece material and eliminate internal stress and other special purposes, it is necessary to remove various pre-technical treatments such as oil, oxide, and internal stress.
2 Postplating postplating
Post-plating technical treatment (such as passivation, hot melting, sealing and hydrogen removal, etc.) for the purpose of enhancing the protective performance, decoration, and other special purposes of the plated parts.
3 chemical polishing chemical polishing
The process of processing metal parts in a certain solution to obtain a smooth, bright surface.
4 chemical degreasing alkaline degreasing
The process of removing oil stains on the surface of parts in an alkaline solution by saponification and emulsification.
5 Electropolishing electropolishing
The process of anodizing metal parts in a suitable solution to make the surface smooth and bright.
6 Electrolytic degreasing
The process of electrolysis of metal parts as anode or cathode in alkaline solution to remove oil stains on the surface of parts.
7 Electrolytic pickling
The process of electrolysis of metal parts as anode or cathode in an electrolyte solution to remove oxides and rust on the surface of parts.
8 bright dipping
A process in which a metal part is immersed in a solution for a short time to form a bright surface.
9 mechanical polishing
The machining process of improving the surface smoothness and brightness of metal parts by means of high-speed rotating polishing wheels coated with polishing paste.
10 organic solvent degreasing solvent degreasing
The process of using organic solvents to remove oil stains on the surface of parts.
11 bright pickling
The process of removing oxides or other compounds from the surface of metal parts by chemical or electrochemical methods to make them bright.
12 roughening roughening
It is a pre-treatment process for electroless plating of non-conductive materials that use mechanical or chemical methods to make the surface of the workpiece micro-rough, changing it from hydrophobicity to lipophilicity, so as to improve the bonding force between the coating and the surface of the workpiece.
13 Sensitization
Immerse the roughened non-conductive parts in a sensitizing solution to adsorb a layer of reducing substances on the surface, so that during subsequent activation treatment, precious metal ions can be reduced on the surface of the parts to form an “activation layer” or “active layer”. Catalytic film”, thereby accelerating the process of electroless plating reaction.
14 amalgamation (blue dip)
The process of immersing metal parts such as copper or copper alloys in a mercury salt solution to form an amalgam on the surface of the parts.
15 brushing
The rotating metal or non-metallic brush wheel (or brush) processes the surface of the workpiece to remove the remaining attachments on the surface and make the surface appear glossy.
16 emulsion degreasing
The process of removing oil stains on the surface of parts with a liquid containing organic solvents, water, and emulsifiers.
17 removal of hydrogen (de-embrittlement )
Metal parts are heated at a certain temperature or
Plating Method
1 chemical vapor deposition chemical vapor deposition
A process in which the deposition layer is produced by coagulating a substrate with a heat-induced chemical reaction or vapor-phase reduction.
2 physical vapor deposition
Overlayers of capping layers are typically deposited in a high vacuum by evaporation and subsequent condensation of the element or compound.
3 chemical passivation chemical passivation
The process of treating metal parts with a solution containing an oxidant to form a very thin passive protective film on the surface.
4 chemical oxidation chemical oxidation
The process of forming an oxide film on a metal surface by chemical treatment.
5 Anodizing
The process of electrolysis of metal parts as anodes in a certain electrolyte to form an oxide film with certain functions (such as protection, decoration, or other functions) on the surface.
6 Electroless plating (autocatalytic plating) autocatalytic plating
On the surface of the activated substrate, the metal ions in the plating solution are catalytically reduced to form a metal coating.
7 Laser electroplating 1aser electroplating
Electroplating under the action of a laser.
8 Flash plating flash(flash plate)
Very short energization times produce electroplating of thin layers.
9 Electroplating
The process of using electrolysis to form a uniform, dense and well-bonded metal or alloy deposition layer on the surface of a workpiece.
10 mechanical plating
In the presence of fine metal powder and a suitable chemical agent, the metal surface is hit with a small hard ball to coat the surface with the fine metal powder.
11 immersion plate
A metal deposit resulting from a displacement reaction in which one metal displaces another from solution, such as:
Fe+Cu2+→Cu+Fe2+
12 Electroforming
The process of making or replicating a metal article by electrolytically depositing metal on a casting mold (which can separate the casting mold from the metal deposit).
13 superimposed current electroplating
Electroplating in which pulsed current or alternating current is superimposed on direct current.
14 bright plating
Under suitable conditions, electroplating with a glossy coating is obtained directly from the plating bath.
15 alloy plating alloy plating
The process of co-depositing two or more metals (including non-metal elements) under the action of an electric current.
16 multiplayer plating
Electroplating in which several metal layers with different properties or materials are successively deposited on the same substrate.
17 strike plating
A method of electrodepositing a thin metal layer in a specific solution at a high current density for a short period of time to improve the bonding force between the deposited coating and the substrate.
18 metal electrodeposition metal electrodeposition
The process of reducing metal ions in solution on electrodes and forming a metal phase by means of electrolysis. Including electroplating, electroforming, electrolytic refining, etc.
19 brush plating
A method of selective electroplating using an electrode or brush connected to the anode and capable of supplying the electrolyte required for electroplating, moving over the part acting as the cathode.
20 periodic reverse plating
Electroplating with periodic changes in the current direction.
21 conversion coating conversion coating
A surface film layer containing the metal compound formed by chemical or electrochemical treatment of a metal, such as a chromate film on zinc or cadmium or an oxide film on steel.
22 rack plating
Electroplating using a hanger to hang the part.
23 Composite plating (dispersion plating) composite plating
The process of obtaining a composite coating by simultaneously depositing metal ions and insoluble non-metallic or other metal particles uniformly suspended in a solution by electrochemical or chemical methods.
24 pulse plating
Electroplating with pulse power instead of DC power.
25 Blueing (chemical oxide) of steel
The process of heating steel parts in the air or immersing them in an oxidizing solution to form a usually blue (black) oxide film on the surface.
26 high-speed electrodeposition
In order to obtain high deposition rates, special measures are used to carry out the electroplating process at extremely high cathodic current densities.
27 barrel plating
Parts are electroplated in rotary vessels. Suitable for small parts.
28 plating on plastics
The process of electrodepositing metal coatings on plastic parts.
29 Phosphating
The process of forming an insoluble phosphate protective film on the surface of steel parts.
Test Inspection
1 Atmospheric corrosion test
A test to check the atmospheric corrosion resistance of the coating was carried out according to the specified method in the exposure field of different climatic zones.
2 neutral salt spray test (NSS-test)
The corrosion resistance of the coating is tested by the specified neutral salt spray.
3 Discontinuous water film water break
The phenomenon is that the water film of the workpiece surface is discontinuous due to uneven wettability caused by contamination, which is a method to check the degree of cleaning.
4 pH meter pH meter
An instrument for measuring the pH of a solution.
5 porosity
The number of pinholes per unit area.
6 Internal stress
During the electroplating process, the crystal structure of the coating is changed due to various reasons, so that the coating is stretched or compressed, but because the coating has been fixed on the substrate, the coating is in a state of stress. This internal force acting on the coating is called internal force. stress.
7 conductivity gauge
An instrument for measuring the conductivity of an electrolyte solution.
8 coulomb meter (electricity meter) coulomb meter
An instrument that measures the amount of electricity passing through according to the mass or volume (for gases) of the precipitates on the electrodes during electrolysis.
9 rotating disk electrode
An electrode for measuring the diffusion coefficient and electrochemical parameters of a solution system. It is a metal rod embedded in a concentric plastic cylinder, the bottom surface of the metal rod is the working surface of the electrode, the electrode is connected with the rotating shaft of the rotating motor, and the whole is fixed on a stable frame, the working surface of the electrode is perpendicular to the rotating shaft, and its center is aligned with the rotating shaft. axis. In this way, when the electrode rotates, the liquid phase close to the working surface of the electrode establishes a uniform and stable diffusion layer whose thickness is related to the rotation speed.
10 rotating ring disk electrode
The ring-disk electrode is an electrode equipped with a concentric ring on the working surface of the disk electrode, and the ring and the disk are separated by a thin layer of insulating material. Ring electrodes are used to detect soluble reaction products on disk electrodes, and ring disk electrodes are also commonly used electrodes for electrochemical testing.
11 Pinhole pores
Tiny channels penetrate from the surface of the coating to the bottom of the coating or to the base metal.
12 copper accelerated salt spray (CASS test).
An accelerated corrosion test was conducted with an aqueous solution of sodium chloride containing specified copper salts and acetic acid as a spray.
13 reference electrode reference electrode
Equilibrium electrode potential is a very stable and highly reversible half-cell that can be formed as a galvanic cell with another half-cell to determine the latter’s electrode potential.
14 calomel electrode calomel electrode
A half-cell consisting of mercury, mercurous chloride, and potassium chloride solution of a certain concentration (eg, a saturated solution).
15 Solderability solderability
The ability of a plated surface to be wetted by molten solder.
16 hardness
The ability of a coating to resist being scratched or pressed into its surface by other objects is an important mechanical property of a coating. According to the different measurement methods, different values can be used to express hardness, such as Brinell hardness, Rockwell hardness, Vickers hardness, Shore hardness, and Knoop hardness. Hardness is usually measured with a microhardness tester.
17 Metal discoloration tarnish
Changes in the color of the metal or coating surface due to corrosion, such as darkening, discoloration, etc.
18 dropping corrosion test dropping corrosion test
A test method for testing the corrosion resistance of the protective layer on the surface of the sample by allowing a specific corrosive liquid to be dripped on the surface of the sample in a controlled manner.
19 glass electrode
An electrode that uses a thin glass membrane to separate two solutions to generate a potential difference is often used to measure the pH of a solution.
20 adhesion
A measure of the bond strength between the coating and the substrate is expressed in terms of the force required to separate the coating from the substrate.
21 Haring cell
A rectangular tank made of insulating material, the anode in the tank corresponds to the two cathodes far and near respectively and is used to estimate the dispersion ability of the plating solution and the degree of electrode polarization.
22 potentiostatic method
In order to obtain the relationship between the electrode potential and the current density, the electrode potential of the research electrode can be controlled to change according to a certain law, and the corresponding current density can be measured at the same time.
23 galvanostatic method
In order to obtain the relationship between the current density and the electrode potential, the current density of the research electrode can be controlled to change according to a certain law, and the corresponding electrode potential can be measured at the same time.
24 AC current method a.c method
It is a method to excite the electrode with a small amplitude sine wave alternating current, and from the response of the electrode potential, some parameters of the electrode process can be obtained.
25 Dendritic trees
Rough, loose dendritic, or irregularly raised deposits that form on cathodes (especially edges and other areas of high current density) during electroplating.
26 brittleness
The ability of the coating to withstand the degree of deformation is mainly determined by the coating material and its internal stress.
27 peeling
The phenomenon in which the coating is separated from the substrate in the form of flakes.
28 bubbly blister
A bulge-like defect is caused in the plating layer due to the loss of bonding between the plating layer and the underlying metal.
29 Stripping spalling
Chipping or peeling of the coating surface layer due to some cause (eg uneven thermal expansion or shrinkage).
30 orange peel
A finish that resembles an orange-peel-like appearance.
Pre-plating and Post-plating
1 preplating preplating
In order to expose the real surface of the workpiece material and eliminate internal stress and other special purposes, it is necessary to remove various pre-technical treatments such as oil, oxide, and internal stress.
2 Postplating postplating
Post-plating technical treatment (such as passivation, hot melting, sealing and hydrogen removal, etc.) for the purpose of enhancing the protective performance, decoration, and other special purposes of the plated parts.
3 chemical polishing chemical polishing
The process of processing metal parts in a certain solution to obtain a smooth, bright surface.
4 chemical degreasing alkaline degreasing
The process of removing oil stains on the surface of parts in an alkaline solution by saponification and emulsification.
5 Electropolishing electropolishing
The process of anodizing metal parts in a suitable solution to make the surface smooth and bright.
6 Electrolytic degreasing
The process of electrolysis of metal parts as anode or cathode in alkaline solution to remove oil stains on the surface of parts.
7 Electrolytic pickling
The process of electrolysis of metal parts as anode or cathode in an electrolyte solution to remove oxides and rust on the surface of parts.
8 bright dipping
A process in which a metal part is immersed in a solution for a short time to form a bright surface.
9 mechanical polishing
The machining process of improving the surface smoothness and brightness of metal parts by means of high-speed rotating polishing wheels coated with polishing paste.
10 organic solvent degreasing solvent degreasing
The process of using organic solvents to remove oil stains on the surface of parts.
11 bright pickling
The process of removing oxides or other compounds from the surface of metal parts by chemical or electrochemical methods to make them bright.
12 roughening roughening
It is a pre-treatment process for electroless plating of non-conductive materials that use mechanical or chemical methods to make the surface of the workpiece micro-rough, changing it from hydrophobicity to lipophilicity, so as to improve the bonding force between the coating and the surface of the workpiece.
13 Sensitization
Immerse the roughened non-conductive parts in a sensitizing solution to adsorb a layer of reducing substances on the surface, so that during subsequent activation treatment, precious metal ions can be reduced on the surface of the parts to form an “activation layer” or “active layer”. Catalytic film”, thereby accelerating the process of electroless plating reaction.
14 amalgamation (blue dip)
The process of immersing metal parts such as copper or copper alloys in a mercury salt solution to form an amalgam on the surface of the parts.
15 brushing
The rotating metal or non-metallic brush wheel (or brush) processes the surface of the workpiece to remove the remaining attachments on the surface and make the surface appear glossy.
16 emulsion degreasing
The process of removing oil stains on the surface of parts with a liquid containing organic solvents, water, and emulsifiers.
17 removal of hydrogen (de-embrittlement )
Metal parts are heated at a certain temperature or the processes methods to drive out the process of absorbing hydrogen inside the metal.
18 Annealing annealing
Annealing is a heat treatment process in which the plated parts are heated to a certain temperature and then slowly cooled after holding for a certain period of time. Annealing treatment can eliminate the absorbed hydrogen in the coating and reduce the internal stress of the coating, thereby reducing its brittleness; it can also change the grain state or phase structure of the coating to improve the mechanical properties of the coating or make it have certain electrical, magnetic or other properties.
19 countercurrent rinsing
A multi-pass cleaning process in which the running direction of the workpiece is opposite to the flow direction of the cleaning water.
20 closed sealing
After the aluminum parts are anodized, in order to reduce the porosity of the oxide film formed by anodization, physical and chemical treatments are carried out in an aqueous solution or a steam medium. Its purpose is to increase the anti-fouling ability and corrosion resistance of the anode cover layer, to improve the persistence of coloration of the cover layer, or to impart other desired properties.
21 dyeing power
The ability of dyes to adhere to anodized films or coatings.
22 stripping
The process of removing the coating on the surface of a part.
23 thermal diffusion thermal diffusion
The process of heat treating a plated part to diffuse the base metal and the deposited metal(s) to form an alloy layer.
24 hot melting
In order to improve the appearance and chemical stability of coatings such as tin or tin-lead alloys, the process of heating the plated parts at a temperature slightly higher than the melting point of the plated metal to melt and recrystallize the surface of the plated layer.
25 coloring coloring
The process of adsorbing organic or inorganic dyes on a porous anodized film to make it appear in various colors.
26 Decolorization
The process of removing color from a colored oxide film with a decolorizer.
27 shot blasting
The process of spraying a metal surface with hard, small balls, such as metal shot, to pressurize the surface to harden it or have a decorative effect.
28 sandblasting
The process of decontamination, rust removal, or roughening by jetting the flow of sand particles against the surface of the workpiece.
29 spray cleaning spray rinsing
A cleaning method that uses a jet of fine liquid to flush the parts to improve the cleaning effect and save water.
30 ultrasonic cleaning
A method of using ultrasonic waves to act on the cleaning solution to more effectively remove oil stains and other impurities on the surface of the workpiece.
31 Weak etching acid dipping
A process in which metal parts are immersed in a certain solution before electroplating to remove the extremely thin oxide film on the surface and activate the surface.
32 Strong pickling
The process of immersing metal parts in a higher concentration and certain temperature etching solution to remove oxides and rust on them.
33 satin plus 212 satin finish
The process of making the surface of the part a diffuse reflection layer. The treated surface has a satin-like non-specular shimmering sheen.
34 barrel burnishing
The process of tumble polishing is carried out by placing the workpiece in a rotating container filled with abrasives and tumble polishing liquid.
35 grinding
The machining process of polishing metal parts with the aid of abrasive wheels improves the surface flatness of the parts.