摘要
利用自生复合法生成的硅相增强Zn-25Al合金,并用自制钠盐对其进行变质处理。经观察发现,Zn-25Al合金的断裂主要是韧性断裂,断裂表面存在大量的撕裂棱和韧窝;随着含Si量的增大,合金的断裂由韧性断裂变为混合型断裂,Si作为脆性相造成了合金的沿晶断裂;变质剂改变了硅相的形貌,初生硅由块状变为球团状或杆状,使合金沿晶断裂消耗能量增加,断口上的韧性断裂面增大,而脆性断裂面减少。合金的铸造缺陷进一步加大了合金的断裂。
Zn-25Al Alloy reinforced by silicon phases using in-situ composite method, and the modification of the composites by sodium salt was performed. The results show that it belongs to ductile fracture with lots of dimples and tearing rodges. With increasing Si content, the fracture mode transforms from ductile fracture to a mixed fracture mode, because intergranular occurs due to the existence of Si. The morphology of primary Si phase can be modified from blocky to spheric/or lathy-like in shape, which makes it to absorb more energy to fracture. The ductile fracture surfaces are larger, while the brittle fracture surfaces are smaller. Casting defects further improve the fracture of alloys.
出处
《铸造技术》
CAS
北大核心
2009年第7期892-895,共4页
Foundry Technology
关键词
硅相
ZA合金
变质剂
断裂特性
Si phase
ZA alloy
Modification
Fracture performance
