| 摘要 |
PURPOSE:To adhere a boron-nickel layer to light metal or light alloy as base metal more tightly and to improve the physical characteristics of a diaphragm by adhering nickel-boron alloy to the diaphragm of light metal or light alloy by chemical plating. CONSTITUTION:Ethylene diamine, triethylene tetramine, citric acid, tartaric acid, succinic acid, etc., are used as a complexing agent for nickel ions in order to miximize the solubility of a reducing agent in plating liquid, whose pH value is set to above 12.5. When a boron hydride compound is used as the reducing agent, nickel and boron are deposited at the same time as shown by two reaction formulas I to form an alloy layer on the diaphragm. Those reaction formulas hold at the same time, so a metallic compound consisting of >=2% boron and nickel is produced. Therefore, the diaphragm made of light metal or light alloy of aluminum, magnesium, titanium, etc., is activated and then the nickel- boron alloy is adhered. Further, organic amine, etc., are usable as the reducing agent. |
