45钢与QAl9-4铝青铜的界面冶金分析

Analysis of Interface Metallurgy Bonding of 45 Steel and QAl9-4 Aluminum Bronze

采用高温真空＋气氛熔铸的复合工艺制备了QA19-4铝青铜与45钢双金属复合材料,并对其界面的微观组织结构、元素分布进行了系统研究.结果表明,在真空度为（10-2～10-3）Pa下,加热到1 150℃保温90 min,降温时通入纯氩气的高温真空熔铸法可制备铜钢双金属复合材料,其组织分布合理,复合界面出现“舌状”、“锯齿状”突起,界面清晰无气孔、夹杂等缺陷,存在40～200 μm过渡区域,有合金元素互扩散现象和少量中间相形成;断口发生在铝青铜侧,呈现撕裂棱加韧窝的准解理断裂特征;复合界面主要存在熔合结合、表面扩散和晶界渗透三种复合形式,其中表面扩散和晶界扩散是形成过渡区的主要因素.

In this paper, QA19-4 aluminum bronze and 45 steel bimetal composite material was prepared by the high temperature vacuum and atmosphere casting process. The interfacial microstructure and element distribution of the copper steel composites were observed. The results show that copper steel bimetal composites can be fabricated when the following conditions were satisfied such as the vacuum degree in the range of （102-10-3） Pa and heat retaining at 1 150℃ for 90 rnin and cooling with pure argon atmosphere. The ligulate and zigzag phenomenon appears in bonding interface of copper and steel composites .There is 40-200μm width clear transition area and the porosity and inclusions defects are not observed in the transition area, but alloy elements diffusion phenomenon and some interphase was observed. The fracture mechanism of sample is tearing edge and toughening features of quasi cleavage fracture. There are three composite forms, namely fusion, surface diffusion and grain boundary penetration. And grain boundary diffusion is the main factor that forms the transition zone.