碳纤维表面化学镀钴–镍合金工艺研究

Study on electroless cobalt–nickel alloy plating on surface of carbon fiber

采用以硫酸钴和硫酸镍为主盐,柠檬酸钠为配位剂,次磷酸钠为还原剂的镀液,在碳纤维表面化学镀钴-镍合金,得到碳纤维/钴-镍合金复合粒子。研究了次磷酸钠含量、氨水含量和温度对化学镀所得复合粒子的导电性和微观形貌的影响,获得碳纤维化学镀钴-镍合金镀层的最优配方和工艺为:NiSO_4·6H_2O 15g/L,COSO_4·7H_2O 15 g/L,NaH_2PO_2·H_2O 30 g/L,Na_3C_6H_5O_7 30 g/L,26%(体积分数)NH_3·H_2O 140 mL/L,温度80℃,时间30 min。在最优工艺条件下所得碳纤维/Co-Ni合金复合粒子的体积电阻率为3.27×10^(-2)Ω·cm,比未镀碳纤维低1个数量级。碳纤维表面的合金镀层均匀、致密,主要由面心立方结构的Co-Ni合金构成。

Carbon fiber/Co-Ni alloy composite particles were prepared by electroless cobalt-nickel plating on the surface of carbon fiber from a bath based on cobalt sulfate and nickel sulfate with sodium citrate as complexant and sodium hypophosphite as reductant. The optimal bath composition and conditions obtained by studying the effects of sodium hypophosphite content, aqueous ammonia content and temperature on the conductivity and morphology of the composite particles are as follows： NiSO4-6H2O 15 g/L, COSO4·7H2O 15 g/L, NaH2PO2·H2O 30 g/L, Na3C6H5O7 30 g/L, 26vo1% NH3·H2O140 mL/L, temperature 80 ℃, and time 30 min. The volume resistivity of carbon fiber/Co-Ni alloy composite particles is 3.27 × 10-2 Ω·cm, which is one order of magnitude lower than that of unplated carbon fiber. The alloy coating on the surface of carbon fiber is uniform, compact, and mainly composed of face-centered cubic Co-Ni alloy.