摘要
采用显微金相、扫描电镜、能谱分析及数值模拟等方法对挤压铸造成形行星盘铸件在机械加工过程中的失效机理进行了分析。结果表明 :残留在枝晶间的共晶液体受挤压使先析出的枝晶结构破坏 ,沿着枝晶间的通道向铸件外表面流动 ,在随后冷却凝固过程中形成了表面共晶偏析组织。偏析组织中Si的含量较高 ,使材料塑性降低 ,该组织与氧化夹杂共同作用 ,使毛坯在随后的加工过程中出现裂纹破坏。
The failure mechanism of the planet tray casting during the machining process has been analyzed by optical microscope by optical microscope、SEM、EDS and simulation. The squeezed eutectic liquid destroys the dendrite structure which is precipitated at first, and flows toward surface of casting along the channels of dendrites. The surface eutectic segregation is come into being during the cooling solidification process later. High content of Si in segregation reduces plasticity. Owing to the negative impact of the eutectic segregation and the oxide, the blank is spoiled with the advent of the macro-crack in the process of manufacture late.
出处
《铸造技术》
CAS
北大核心
2004年第5期344-345,348,共3页
Foundry Technology
关键词
行星盘铸件
挤压铸造
共晶偏析
失效
Planet tray casting
Squeeze casting
Eutectic segregation
Failure
