无铅易切削镁黄铜的组织与性能

Microstructure and Properties of Cutting Lead-free Brass Containing Magnesium

采用熔铸、挤压、拉拔的方法生产出了以镁代铅的环保型易切削黄铜材。对易切削黄铜的微观组织进行了观察,并对其力学、化学和切削性能分别进行了研究。结果表明:镁黄铜晶内和晶间有白色和黑色的球状第二相粒子分布,该粒子为金属间化合物,具有脆而不硬的特点,对提高合金切削性能有利。半硬态镁黄铜的抗拉强度为550 MPa,屈服强度为280 MPa,延伸率为16.30%,断面收缩率为32.4%。从切削过程中切削力的大小以及切屑的形貌、大小可以判断,镁黄铜的切削性能接近于C3604铅黄铜。镁黄铜在酸中和盐中的耐蚀性均较好,比较而言耐盐性要好一些。

A new environmental friendly cutting brass containing magnesium instead of lead was produced by casting, extruding and drawing. Its microstructure was observed and its mechanical, chemical and cutting properties were stutied. The results show that the global secondary particles which are intermetallics and are of brittleness and softness distribute in grains and on grainboundries, which is helpful for cutting. The tensile strength, yield strength, elongation and variation of area of halfhard brass containing magnesium are 550 MPa, 280 MPa, 16.30% , 32.4% respectively. The cutting property of brass containing magnesium corresponds to that of brass containing lead C3604 by the size and appearance of chips and the cutting force. The brass containing magnesium has excellent corrosion resistance.