| 摘要 |
A bi-stable magnetic film core is made by electroplating a nickel-iron coating on to a conductive non-magnetic surface formed on a non-magnetic base member by producing a metal salt in situ thereon and immersing the conductive surface in an aged solution of sodium or potassium mercurous cyanide. A silver coating is formed on a flat, rod-like or filamentary base member of glass, quartz, synthetic resin or a copper beryllium alloy by cleaning, sensitizing by immersion in stannous chloride solution and, after rinsing, spraying on silver solution and a silver spray reducer using nitrogen gas. The base is moved through the spray zone several times at increasing speeds. After rinsing, the silver coated base is immersed for a few seconds in an aged solution of sodium or potassium mercurous cyanide so that an alloy of silver and mercury is formed on the surface of the silver coating. A thin film of nickel and iron (97% /sB2%) is then electroplated on to the silver coating and a cover of urethane resin is applied. A filament, rod or other base on which the conducting base is formed may be passed with about 3 inches exposed through the electrolyte at about 5 inch per minute, the plating current being from 12-25 milliamps. A tubular or spiral anode may be used. The electrolyte may consist of 290 grams of Fe Cl2.4H2O, 12 grams of Ni Cl2.6H2O and 238 grams of Ca Cl2 per litre of water solution with addition of dilute H Cl to bring the pH value to 1.00/sB0.05. Enough iron powder or iron wool may be added to ensure that the solution is ferrous. |
