电镀银SILVER PLATING
1. INTRODUCTION 介绍
A. The data in this subject comes from Boeing Process Specification BAC5715. The airline has a copy of the Boeing Process Specification Manual.
本主题中的数据来自波音工艺规范 BAC5715。航空公司有一本《波音工艺规范手册》。
B. The data is general. It is not about all situations or specific installations. Use this data to help you write minimum standards.
数据是通用的。并不涉及所有情况或特定安装。使用此数据可帮助您编写最低标准。
C. The procedure will make silver plating that agrees with QQ-S-365. Equivalent procedures can be used.
该程序可制成与 QQ-S-365 一致的电镀银。可使用等效程序。
D. The types and grades are the same as those specified in QQ-S-365:
类型和等级与 QQ-S-365 规定的相同：
Type 1 — Matte (dull, not shiny)
类型 1 — 哑光（暗淡，无光泽）
Type 2 — Semibright (partially shiny)
类型 2 — 半亮（部分发亮）
Type 3 — Bright (shiny)
类型 3 — 明亮（有光泽）
Grade A — With supplementary tarnish-resistant chromate treatment
A 级 — 经过抗污铬酸盐补充处理
Grade B — Without supplementary tarnish resistant treatment
B 级 — 无辅助防变色处理
E. Do not use this procedure to silver plate steels heat treated above 220 ksi.
不要使用此程序对热处理超过 220 ksi 的钢材进行电镀。
F. Refer to SOPM 20-00-00 for a list of all the vendor names and addresses.
请参阅 SOPM 20-00-00，了解所有供应商的名称和地址。
2. MATERIALS 材料
A. Silver cyanide — Plating grade
氰化银-电镀级
B. Sodium cyanide, 97% NaCN minimum — Plating Grade
氰化钠，最低含量为 97% NaCN — 电镀级
C. Potassium cyanide, 98% KCN minimum — Plating Grade
氰化钾，最低含量为 98% KCN — 电镀级
D. Sodium carbonate, anhydrous, technical — O-S-571
工业级无水碳酸钠 — O-S-571
E. Potassium carbonate, anhydrous, technical
工业级无水碳酸钾
F. Carbon disulfide, technical
工业用二硫化碳
G. Silver anodes, 999.5 + fine, minimum
阳极银，999.5 + 精制，最小值
H. Abrasives for scouring
擦洗用磨料
(1) Wyandotte F-1013, V54151
(2) Pumice, Grade FF
浮石，FF 级
(3) Tripoli Powder
I. Hydrochloric acid, 20 degree Baume’, technical — O-H-765
盐酸，20 度 Baume’，工业级 — O-H-765
J. Inhibitors
抑制剂
(1) Acryl, V61102
(2) Polyrad 1110A, V28284
(3) Rodine 123, V84063
K. Potassium hydroxide, technical
工业氢氧化钾
L. Nitric acid, 40- or 42-degree Baume’, technical — O-N-350
硝酸，40 或 42 度 Baume’，工业级 — O-N-350
M. Sodium thiosulfate, crystal — USP grade
硫代硫酸钠，晶体 — USP 级
N. Silver-Lume Brightener A, V27201 or V76323
银色光亮剂 A，V27201 或 V76323
O. Silver-Lume Brightener B, V27201 or V76323
银色光亮剂 B，V27201 或 V76323
P. Chromate Compound — Iridiate 18-P, V70308
铬酸盐化合物 – 铱化物 18-P，V70308
Q. Anode bags, woven nylon
尼龙编织阳极袋
R. Masking Materials
遮蔽材料
(1) Turco No. 522 or 544, V61102
(2) Microshield Stopoff Lacquer, V01058
(3) Micromask, V01058
(4) Platers Tape, yellow, V3M808
S. Endox 214 solution (Ref SOPM 20-30-03)
T. Nickel strike solution (Ref SOPM 20-42-09)
击镍溶液（参考 SOPM 20-42-09）
3. SOLUTION PREPARATION 溶液配制
WARNING :THE SILVER PLATING SOLUTIONS CONTAIN CYANIDE SALTS AND ARE VERY POISONOUS. DO NOT LET ACIDS GET INTO SOLUTIONS. DO NOT LET SOLUTIONS TOUCH EYES, SKIN, OR CLOTHING. DO NOT BREATHE MIST OR VAPOR. KEEP CYANIDES AWAY FROM HEAT, SPARKS, AND OPEN FLAMES.
警告 :电镀银溶液含有氰化物盐，毒性很大。不要让酸进入溶液。不要让溶液接触眼睛、皮肤或衣物。不要吸入雾气或蒸气。氰化物要远离热源、火花和明火。
A. Silver Strike Bath
银击槽
(1) Clean tank thoroughly and add 1/2 the total amount water.
彻底清洗槽，加入总量 1/2 的水。
(2) Add 60 pounds (9.5 oz/gal) sodium cyanide or potassium cyanide and 6 pounds (1.0 oz/gal) sodium carbonate or potassium carbonate per 100 gallons of final solution. Stir solution until these chemicals are dissolved.
每 100 加仑最终溶液加入 60 磅（9.5 盎司/加仑）氰化钠或氰化钾和 6 磅（1.0 盎司/加仑）碳酸钠或碳酸钾。搅拌溶液，直至这些化学品溶解。
(3) Add 3.75 pounds (0.6 oz/gal) silver cyanide per 100 gallons of final solution. Add this chemical slowly with constant stirring of solution.
每 100 加仑最终溶液加入 3.75 磅（0.6 盎司/加仑）氰化银。在不断搅拌溶液的情况下缓慢加入该化学品。
(4) Add water to fill tank to operating level.
加水至槽的操作水平。
(5) Control the solution temperature at room temperature to 90°F.
将溶液温度控制在室温至 90°F。
(6) Control solution at 8.0-11.4 oz/gal free sodium cyanide.
将溶液控制在 8.0-11.4 盎司/加仑游离氰化钠。
(7) Control current density at 40 to 100 asf.
将电流密度控制在 40 至 100 asf。
(8) Use steel anodes as required.
根据需要使用钢阳极。
B. Silver Plate Solution for Matte and Semibright Plating
亚光和半光电镀用镀银溶液
(1) Clean tank thoroughly and add 1/2 the total amount water.
彻底清洗槽，加入总量 1/2 的水。
(2) Add 43 pounds (7.0 oz/gal) potassium cyanide and 31 pounds (5.0 oz/gal) potassium carbonate per 100 gallons of final solution. Stir solution until these chemicals dissolve.
每 100 加仑最终溶液加入 43 磅（7.0 盎司/加仑）氰化钾和 31 磅（5.0 盎司/加仑）碳酸钾。搅拌溶液，直至这些化学品溶解。
(3) Add 25 pounds (4.0 oz/gal) silver cyanide per 100 gallons of final solution. Add this chemical slowly and stir constantly.
每 100 加仑最终溶液加入 25 磅（4.0 盎司/加仑）氰化银。缓慢加入并不断搅拌。
(4) Add water to fill tank to operating level.
加水至槽的操作水平。
(5) Control the solution temperature at room temperature to 90°F.
将溶液温度控制在室温至 90°F。
(6) Control solution at 13.4 (maximum) oz/gal potassium carbonate, 4.0-6.0 oz/gal free potassium cyanide, and 2.9-4.0 oz/gal silver metal.
将溶液控制在 13.4（最高）盎司/加仑碳酸钾、4.0-6.0 盎司/加仑游离氰化钾和 2.9-4.0 盎司/加仑金属银。
(7) Control current density at 12 asf, maximum.
将电流密度控制在 12 安培（最大值）。
(8) Control anode to cathode ratio at 1 to 1, minimum.
阳极与阴极的比例控制在 1 比 1（最小值）。
(9) Use silver anodes and anode bags.
使用银阳极和阳极袋。
(10) For Type 1 (matte) plating, brightener per Paragraph 3.B.(11) is permitted, if necessary, to make a smooth finish.
对于类型1 （无光泽）电镀，如有必要，可使用第 3.B.(11)段所述的光亮剂，使镀层光滑。
(11) For Type 2 (semibright) plating, add one of these two brighteners:
对于类型 2（半光亮）电镀，可添加以下两种光亮剂中的一种：
(a) Dissolve sodium thiosulfate in water to make a thin paste. Add small quantities of this to the plating bath, as necessary to make a semibright plate.
将硫代硫酸钠溶于水，制成稀糊状。根据需要在电镀液中加入少量，以制成半光亮电镀板。
WARNING :CARBON DISULFIDE IS VERY FLAMMABLE. FRICTION CAN CAUSE IGNITION.
警告：二硫化碳非常易燃。摩擦会引起燃烧。
(b) As an alternative, use this carbon disulfide brightener: 9.5 oz/gal potassium cyanide and 1.0 oz/gal potassium carbonate in water. First add the potassium cyanide and potassium carbonate to approximately one-half the total volume of water. Stir until these chemicals are dissolved. Add 0.6 oz/gal silver cyanide slowly to the mixture and stir constantly. Then add water to the final volume, to get the specific concentrations of these chemicals. Shake with an excess of carbon disulfide until the mixture is saturated. Add approximately 1/8 fluid ounce of this mixture per gallon of the plating solution.
也可使用二硫化碳光亮剂： 9.5 盎司/加仑氰化钾和 1.0 盎司/加仑碳酸钾加水。首先将氰化钾和碳酸钾加入大约总体积一半的水中。搅拌直至这些化学品溶解。向混合物中缓慢加入 0.6 盎司/加仑氰化银，并不断搅拌。然后加水至最终体积，以获得这些化学品的特定浓度。加入过量二硫化碳摇匀，直至混合物饱和。每加仑电镀溶液中加入约 1/8 液盎司该混合物。
C. Silver Plate Solution for Bright Plating
用于光亮电镀的镀银溶液
(1) Clean tank thoroughly and add 1/2 the total amount water.
彻底清洗槽，加入总量 1/2 的水。
(2) Add 100 pounds (16.0 oz/gal) potassium cyanide and 19 pounds (3.0 oz/gal) potassium carbonate per 100 gallons of final solution. Stir solution until these chemicals are dissolved.
每 100 加仑最终溶液加入 100 磅（16.0 盎司/加仑）氰化钾和 19 磅（3.0 盎司/加仑）碳酸钾。搅拌溶液，直至这些化学品溶解。
(3) Add 37.5 pounds (6.0 oz/gal) silver cyanide per 100 gallons of final solution. Add this chemical slowly and stir constantly.
每 100 加仑最终溶液加入 37.5 磅（6.0 盎司/加仑）氰化银。缓慢加入并不断搅拌。
(4) Add water to fill tank to operating level.
加水至槽的操作水平。
(5) Control the solution temperature at 70-120°F.
将溶液温度控制在 70-120°F。
(6) Control solution at 3.0-10.0 oz/gal potassium carbonate, 12.0-14.0 oz/gal free potassium cyanide, and 4.5-6.0 oz/gal silver metal.
将溶液控制在 3.0-10.0 盎司/加仑碳酸钾、12.0-14.0 盎司/加仑游离氰化钾和 4.5-6.0 盎司/加仑金属银。
(7) Control current density at 10 asf when the solution temperature is 70-75°F. Higher current densities can be used at higher solution temperatures.
溶液温度为 70-75°F时，电流密度控制在 10 asf。
(8) Control anode to cathode ratio at 1 to 1, minimum, for current density up to 10 asf. Increase the ratio for higher current densities.
电流密度不超过 10 安培时，阳极与阴极的比例控制在 1 比 1（最小值）。电流密度越高，比率越大。
(9) Use silver anodes and anode bags.
使用银阳极和阳极袋。
(10) Add Silver-Lume Brighteners A and B and maintain the concentration of each independently to produce a bright plate. Use the manufacturer’s instructions for makeup and control.
加入银亮剂 A 和 B，并保持各自的浓度，以产生光亮的电镀层。使用制造商的说明进行配制和控制。
(a) Mix Brightener A at the ratio of 1.0 ounce Brightener A to 8 fluid ounces of a water solution of potassium hydroxide (10.5 oz KOH/gal). Do not prepare this mixture more than one week before it will be used.
按照 1.0 盎司光亮剂 A 与 8 盎司氢氧化钾水溶液（10.5 盎司 KOH/加仑）的比例混合光亮剂 A。在使用前一周内不要配制这种混合物。
(b) Add Brightener B directly to the plating solution and stir.
将光亮剂 B 直接加入电镀溶液并搅拌。
D. Nitric Acid Solution
硝酸溶液
(1) Fill the tank to 9/10 level with water.
在槽中加水至 9/10 水位。
(2) Add an amount of nitric acid equal to 0.5% of the final tank volume (that is, 0.5 gallon nitric acid per 100 gallons of final solution).
加入相当于槽最终容量 0.5%的硝酸（即每 100 加仑最终溶液加入 0.5 加仑硝酸）。
(3) Fill the tank to the operating level with water.
将水槽注满至操作水平。
(4) Use this solution at room temperature. Discard the solution when it is not serviceable.
在室温下使用该溶液。溶液不能使用时应报废。
E. Chromate Solution
铬酸盐溶液
(1) Clean tank thoroughly and add approximately 1/2 the total amount of water.
彻底清洗槽，加入约总水量 1/2 的水。
(2) Add 1.5 ounces chromate compound per gallon of final solution.
每加仑最终溶液加入 1.5 盎司铬酸盐化合物。
(3) Add nitric acid until the pH is 1.5.
加入硝酸，直至 pH 值为 1.5。
(4) Add water to fill tank to operating level.
加水至槽液达到操作水平。
(5) Use this solution at room temperature.
在室温下使用该溶液。
(6) Control the solution at 1.5-3.0 oz/gal chromate compound and pH of 1.5-2.1.
将溶液控制在每加仑铬酸盐化合物 1.5-3.0 盎司，pH 值 1.5-2.1 的水平。
F. Inhibited Hydrochloric Acid Solution (BAC5625 Solution 1)
抑制盐酸溶液（BAC5625 溶液 1）
(1) Add approximately 1/10 the total amount of water to the tank.
向槽中加入约为总量 1/10 的水。
(2) Add 54 gallons hydrochloric acid for each 100 gallons final solution.
每 100 加仑最终溶液加入 54 加仑盐酸。
(3) Add 5 pints inhibitor per 100 gallons of final solution. Use only one inhibitor. Do not mix different inhibitors in the same solution.
每 100 加仑最终溶液加入 5 品脱抑制剂。只使用一种抑制剂。不要在同一种溶液中混合不同的抑制剂。
(4) Add water as necessary to fill the tank to the operating level.
根据需要加水，将槽注满至操作水平。
(5) Use this solution at room temperature.
在室温下使用该溶液。
(6) Control the acid concentration at 23-38 oz/gal HCl. Add 1 fluid ounce inhibitors with each gallon hydrochloric acid (that is, 0.8% by volume) used to adjust the acid concentration.
控制酸浓度为 23-38 盎司/加仑盐酸。每加仑盐酸加入 1 液体盎司抑制剂（即 0.8%（体积）），以调整酸浓度。
(7) Metal contamination limits — Iron, 5 oz/gal maximum; copper, 0.5 oz/gal maximum.
金属污染限值 — 铁，最多 5 盎司/加仑；铜，最多 0.5 盎司/加仑。
G. Uninhibited Hydrochloric Acid Solution (BAC 5625 Solution 19)
无抑制盐酸溶液（BAC 5625 溶液 19）
(1) Add approximately 2/3 the total amount of water to the tank.
向槽中加入约总水量的 2/3。
(2) Add 14 gallons hydrochloric acid for each 100 gallons final solution.
每 100 加仑最终溶液加入 14 加仑盐酸。
(3) Add water as necessary to fill the tank to the operating level.
根据需要加水，将槽注满至操作水平。
(4) Use this solution at temperatures from room temperature to 140°F.
溶液使用温度为室温至 140°F。
(5) Metal contamination limits — Iron, 1 oz/gal maximum
金属污染限值 — 铁，最大 1 盎司/加仑 4.
4. PLATING PROCEDURES 电镀程序
A. Before plating, stress relieve all low alloy and corrosion resistant steel parts per the overhaul instructions. Where no stress relief details are given, stress relieve per SOPM 20-10-02.
电镀前，根据大修说明对所有低合金钢和耐腐蚀钢零件进行应力消除。如无应力释放说明，则按 SOPM 20-10-02 进行应力消除。
B. Surfaces must be water break-free after they were in any processing solution or rinse, except vapor degreasing, solvent cleaning, or emulsion cleaning. A water break-free surface is a surface which keeps a continuous water film for a minimum of at least 30 seconds after it was sprayed or immersion rinsed in clean water at a temperature below 100°F. Clean parts again which show water breaks.
除蒸气脱脂、溶剂清洗或乳液清洗外，表面在任何加工溶液或冲洗后必须无断水。无断水表面是指表面在温度低于 100°F的清水中喷洒或浸泡冲洗后，至少保持 30 秒钟的连续水膜。再次清洗出现断水的零件。
C. Ferrous alloys, nickel alloys, cobalt alloys, and nickel plate:
铁合金、镍合金、钴合金和镍电镀：
(1) Stress relieve, if necessary (Paragraph 4.A.).
必要时消除应力（第 4.A. 段）。
(2) Vapor degrease, emulsion clean, or solvent clean, per SOPM 20-30-03, if required.
如有需要，按照 SOPM 20-30-03 进行蒸汽脱脂、乳剂清洗或溶剂清洗。
(3) Remove rust or scale, per SOPM 20-30-03, if required.
如有需要，按 SOPM 20-30-03 进行除锈或除垢。
(4) Mask and rack, as required.
根据需要进行遮蔽和上架。
(5) Alkaline clean and rinse per SOPM 20-30-03. Do not allow part to dry.
按照 SOPM 20-30-03 进行碱性清洁和冲洗。不要让零件干燥。
(6) For low alloy steel:
用于低合金钢：
CAUTION :THE UNINHIBITED SOLUTION COULD ETCH SURFACE IF PARTS ARE KEPT IN IT FOR MORE THAN 1 MINUTE.
注意 :如果零件在未抑制溶液中停留超过 1 分钟，该溶液可能会腐蚀零件表面。
(a) Put the parts in inhibited hydrochloric acid solution for 2 minutes, or in uninhibited hydrochloric acid solution for 30-60 seconds.
将零件放入抑制盐酸溶液中 2 分钟，或放入未抑制盐酸溶液中 30-60 秒。
(b) Rinse thoroughly in cold water, 2 minutes maximum. Do not allow part to dry.
用冷水彻底冲洗，最多 2 分钟。不要让零件干燥。
(c) If smut is present, remove it by one of these three procedures. When you rinse, do not let the parts dry.
如果存在污垢，可采用上述三种程序之一进行清除。冲洗时，不要让零件干燥。
1) Scour with abrasive and rinse to remove the unwanted material and abrasive.
用研磨剂刮擦并冲洗，以去除不需要的材料和研磨剂。
2) Clean the parts in Endox 214 per SOPM 20-30-03. Anodic clean at 60-80 asf for 2-6 minutes. Then rinse.
按照 SOPM 20-30-03 在 Endox 214 中清洗零件。在 60-80 asf 下阳极清洗 2-6 分钟。然后冲洗。
3) Blast with a mixture of pumice and water. Then rinse.
用浮石和水的混合物喷射。然后冲洗。
(d) As an option to Paragraph 4.C.(6)(a), Paragraph 4.C.(6)(b), Paragraph 4.C.(6)(c) above, electrolytic clean in Endox 214 per Alkaline Cleaning Method 3 in SOPM 20-30-03. Rinse, then electrolytic clean for 1-2 more minutes. Stop on the anodic cycle. Let the Endox solution drain from the parts, but do not rinse or let the parts dry.
作为上文第 4.C.(6)(a)、第 4.C.(6)(b)、第 4.C.(6)(c)段的备选方案，按照 SOPM 20-30-03 中的碱性清洗方法 3 在 Endox 214 中进行电解清洗。冲洗，然后再电解清洗 1-2 分钟。停止阳极循环。让 Endox 溶液从零件中流出，但不要冲洗或让零件干燥。
(e) Put the parts in nickel strike solution within 1 minute. Apply current cathodically for 2 minutes at 30-40 asf.
在 1 分钟内将零件放入镀镍溶液中。以 30-40 安培的电流阴极电流 2 分钟。
(f) Rinse in cold water. Do not let the parts dry.
用冷水冲洗。不要让零件干燥。
(7) For all other ferrous alloys, nickel alloys, cobalt alloys, and nickel plate:
用于所有其他铁合金、镍合金、钴合金和镍电镀：
(a) Nickel strike per SOPM 20-42-09 within 1 minute.
在 1 分钟内按照 SOPM 20-42-09 进行镍处理。
(b) Rinse in cold water. Do not let the parts dry.
用冷水冲洗。不要让零件干燥。
(8) Silver strike within 1 minute. Make cathodic electrical connections to the parts outside the tank, apply power and then silver strike for 30 seconds at 40-100 asf.
在 1 分钟内镀银。在槽外对零件进行阴极电连接，通电，然后以 40-100 asf 的电流击银 30 秒。
(9) Silver plate within 1 minute. Do not let the parts dry. Make cathodic electrical connections to the parts outside the tank, apply power and then silver plate at 12 asf current density for matte or semibright plate, or at 10 asf current density for bright plate, to get the specified plate thickness.
1 分钟内电镀银。不要让零件干燥。与槽外的零件进行阴极电连接，通电，然后以 12 asf 的电流密度（哑光或半光镀银板）或以 10 asf 的电流密度（光亮镀银板）镀银，以获得规定的镀银板厚度。
(10) If the current is stopped during plating, apply anodic current at 4-5 asf for 2.0-2.5 minutes, and then change back to cathodic current per Paragraph 4.C.(9).
如果电镀过程中停止通电，则以 4-5 asf 的阳极电流通电 2.0-2.5 分钟，然后按第 4.C.(9)段改回阴极电流。
(11) Rinse in cold water. As an option, then hot water rinse to help dry the parts.
用冷水冲洗。可选择热水冲洗，以帮助干燥零件。
(12) If the plating is too thin, alkaline etch and clean the parts per SOPM 20-30-03. Then connect the parts anodically, apply power, and put the parts back in the silver plating solution with anodic current at 4-5 asf for 2-5 minutes. Then change back to cathodic current at 5-10 asf and silver plate per Paragraph 4.C.(9) to get the specified plating thickness.
如果电镀层太薄，则按照 SOPM 20-30-03 对零件进行碱性蚀刻和清洗。然后阳极连接零件，通电，将零件放回镀银溶液中，阳极电流为 4-5 asf，持续 2-5 分钟。然后换回 5-10 asf 的阴极电流，并按第 4.C.(9)段的规定进行电镀银，以获得规定的电镀厚度。
(13) If Grade A (tarnish resistant) plating is specified:
如规定使用 A 级（防变色）电镀：
(a) Put the parts in nitric acid solution for 5-15 seconds.
将零件放入硝酸溶液中 5-15 秒。
(b) Rinse.
冲洗。
(c) Put the parts in chromate solution for 0.5-2.0 minutes.
将零件放入铬酸盐溶液中 0.5-2.0 分钟。
(d) Rinse.
冲洗。
(14) Dry with clean, dry compressed air.
用干净、干燥的压缩空气吹干。
(15) Within 8 hours after plating, bake the steel parts as follows:
在电镀后 8 小时内，按以下步骤烘烤钢铁零件：
NOTE: Nickel alloys Inconel 625, 718, and corrosion resistant steels 17-7PH (CH900), A286, 300-series, do not require baking.
注： 镍合金 Inconel 625、718 和耐腐蚀钢 17-7PH（CH900）、A286、300 系列不需要烘烤。
(a) Carburized parts: 5-8 hours at 250-300°F
渗碳零件：在 250-300°F 温度下烘烤 5-8 小时
(b) Threaded parts (unless carburized) and all other ferrous alloy parts, 180-220 ksi: 3 hours minimum at 350-400°F.
螺纹零件（除非渗碳）和所有其他铁合金零件，180-220 ksi：350-400°F 下至少 3 小时。
D. Copper and Copper Base Alloys
铜及铜基合金
(1) Vapor degrease, emulsion clean, or solvent clean, per SOPM 20-30-03, if necessary.
如有必要，按照 SOPM 20-30-03 进行蒸汽脱脂、乳剂清洗或溶剂清洗。
(2) Remove rust or scale per SOPM 20-30-03, if necessary.
如有必要，按照 SOPM 20-30-03 除锈或除垢。
(3) Silver plate within 1 minute. Do not let the parts dry. Make cathodic electrical connections to the part outside the tank, apply power, and then silver plate at 12 asf current density for matte or semibright plate, or at 10 asf current density for bright plate, to get the specified plate thickness.
在 1 分钟内电镀。不要让零件干燥。在槽外对零件进行阴极电连接，通电，然后以 12 asf 的电流密度对无光泽或半光亮镀层进行镀银，或以 10 asf 的电流密度对光亮镀层进行镀银，以获得规定的镀层厚度。
(4) If the current is stopped during plating, apply anodic current at 4-5 asf for 2.0-2.5 minutes, and then change back to cathodic current per Paragraph 4.D.(3).
如果电镀过程中停止通电，则以 4-5 asf 的阳极电流通电 2.0-2.5 分钟，然后按第 4.D.(3)段改回阴极电流。
(5) Rinse in cold water. As an option, then hot water rinse to help dry the part.
用冷水冲洗。可选择热水冲洗，以帮助干燥零件。
(6) If the plating is too thin, alkaline etch and clean the parts per SOPM 20-30-03. Then connect the parts anodically, apply power, and put the parts back in the silver plating solution with anodic current at 4-5 asf for 2-5 minutes. Then change back to cathodic current at 5-10 asf and silver plate per Paragraph 4.D.(3) to get the specified plating thickness.
如果电镀层太薄，则按照 SOPM 20-30-03 对零件进行碱性蚀刻和清洗。然后阳极连接零件，通电，将零件放回镀银溶液中，阳极电流为 4-5 asf，持续 2-5 分钟。然后换回 5-10 asf 的阴极电流，并按第 4.D.(3)段的规定电镀银，以获得规定的电镀厚度。
(7) If Grade A (tarnish resistant) plating is specified:
如规定使用 A 级（防变色）电镀：
(a) Put the parts in nitric acid solution for 5-15 seconds.
将零件放入硝酸溶液中 5-15 秒。
(b) Rinse.
冲洗。
(c) Put the parts in chromate solution for 0.5-2.0 minutes.
将零件放入铬酸盐溶液中 0.5-2.0 分钟。
(d) Rinse.
冲洗。
(8) Dry with clean, dry compressed air.
用干净、干燥的压缩空气吹干。
E. Aluminum Alloys
铝合金
(1) Prepare the parts per SOPM 20-42-04.
按照 SOPM 20-42-04 准备零件。
(2) Silver plate within 1 minute. Do not let the part dry. Make cathodic electrical connections to the part outside the tank, apply power, and then silver plate at 12 asf current density for matte or semibright plate, or at 10 asf current density for bright plate, to get the specified plate thickness.
在 1 分钟内电镀。不要让零件干燥。在槽外对零件进行阴极电连接，通电，然后以 12 asf 的电流密度对哑光或半光镀层进行镀银，或以 10 asf 的电流密度对光亮镀层进行镀银，以获得规定的镀层厚度。
(3) If the current is stopped during plating, apply anodic current at 4-5 asf for 2.0-2.5 minutes, and then change back to cathodic current per Paragraph 4.E.(2).
如果电镀过程中停止通电，则以 4-5 asf 的阳极电流通电 2.0-2.5 分钟，然后按第 4.E.(2)段改回阴极电流。
(4) Rinse in cold water. As an option, then hot water rinse to help dry the part.
用冷水冲洗。可选择热水冲洗，以帮助干燥零件。
(5) If the plating is too thin, alkaline etch and clean the parts per SOPM 20-30-03. Then connect the parts anodically, apply power, and put the parts back in the silver plating solution with anodic current at 4-5 asf for 2-5 minutes. Then change back to cathodic current at 5-10 asf and silver plate per Paragraph 4.E.(2) to get the specified plating thickness.
如果电镀太薄，则按照 SOPM 20-30-03 对零件进行碱性蚀刻和清洗。然后阳极连接零件，接通电源，将零件放回镀银溶液中，阳极电流为 4-5 asf，持续 2-5 分钟。然后换回 5-10 asf 的阴极电流，并按第 4.E.(2)段的规定电镀银，以获得规定的电镀厚度。
(6) If Grade A (tarnish resistant) plating is specified:
如规定使用 A 级（防变色）电镀：
(a) Put the parts in nitric acid solution for 5-15 seconds.
将零件放入硝酸溶液中 5-15 秒。
(b) Rinse.
冲洗。
(c) Put the parts in chromate solution for 0.5-2.0 minutes.
将零件放入铬酸盐溶液中 0.5-2.0 分钟。
(d) Rinse.
冲洗。
(7) Dry with clean, dry compressed air.
用干净、干燥的压缩空气吹干。
(8) Bake parts at 200-225°F for 1 hour, or put in boiling water for 1 hour. Use water low in chlorides and sulfides, to help prevent tarnishing of the silver plate.
将零件在 200-225°F 下烘烤 1 小时，或放入沸水中煮 1 小时。使用氯化物和硫化物含量低的水，以防止电镀银变色。
5. QUALITY CONTROL 质量控制
A. The silver plate must be smooth, fine grained, and have no blisters, pits, nodules, burns or other defects, or separation when examined without magnification.
电镀银必须光滑、纹理细腻，无水泡、凹坑、结节、烧伤或其他缺陷，不用放大镜检查时无分离现象。
B. On parts other than aluminum, the plating must not come off when tested per BSS7235.
在铝以外的零件上，按照 BSS7235 进行测试时，电镀层不得脱落。
C. Unless specified by the overhaul instructions, the minimum thickness must be 0.0005 inch. Measure the thickness with a procedure that is accurate within +/- 10%.
除非大修说明规定，最小厚度必须为 0.0005 英寸。使用精确度在 +/- 10% 范围内的程序测量厚度。
D. Unless specified by the overhaul instructions, the thickness requirements are for only visible surfaces which can be touched by a ball 0.75 inch in diameter. The plating must be continuous on all surfaces touched by the plating current.
除非大修说明书规定，厚度要求仅适用于直径 0.75 英寸的球可触及的可见表面。电镀电流触及的所有表面的电镀层必须是连续的。