摘要
研究了四种不同磷含量的镍磷合金镀层结构以及热处理对组织和性能的影响.结果表明,随磷含量的增加.镀层的结构由晶态→晶态→非晶态→非晶态变化.镍磷合金镀层经时效热处理后,晶态合金镀层从过饱和固溶体中析出新相,非晶态合金镀层发生晶化过程,同时析出新相.315℃以上温度时效处理后,可得到镍和Ni_3P两相组织。经加热时效处理后,镀层的硬度随加热温度的升高呈下抛物线型变化,在400℃时效30分钟可得到硬度的极大值.镀态镀层的耐磨性较差,经时效处理后镀层的耐磨性能提高,600℃时效处理的镀层具有较好的耐磨性。
This paper deals with the coating structure of four various phosphorus content and the effects of heat treatment on structure and properties.The results show that the structure for deposited layers of nickel-phosphorus alloy is changed from crystalline to crystalline+ noncrystalline to noncrystalline with an inerease of phosphorus content.After ageing heat treatmedt of chemical deposited nickel-phosphorus alloy coating,the new phase is precipitated from supersaturated solid solution for crystalline alloy coating,the crystallizing process takes place for noncrystalline alloy coating,at the same time,the new phase is precipitated. After ageing treatment at above 315℃.nickel plus Ni_3P duplex can be obtained.The hardness after ageing treatment is varied as a lower-parabola with an increase of heated temperature, when ageing for 30min.at 400℃,the maximum value of hardness can be obtained.The wear resistance of coating is lower at deposited case,but it can be increased after ageing,the coating layer after ageing at 600℃ has higher wear resistance.
