烧结钽棒轧制时端头开裂的原因分析

Ends sintered tantalum rod rolling cracking cause analysis

针对烧结后钽棒在轧制时端头开裂的问题进行了分析研究,对开裂的端头进行了定点取样分析其密度、化学杂质元素和金相组织,并采用扫描电镜对开裂端头进行形貌观察,综合分析结果表明,钽棒端头密度低,且氧、氮含量较高,表面有裂口,内部有孔洞、夹杂物等,是造成端头轧制时开裂的主要原因。钽坯料垂熔烧结时端头烧结不充分,除杂效果差,杂质相沿晶界析出时容易弱化金属晶界的结合强度,从而降低金属的塑性,受冲击时容易开裂,是根本原因。

Sintered tantalum rod end rolling head cracking problem analysis,tip cracking the designated sampling and analysis of its density,chemical impurity elements and microstructure using scanning electron microscopy and shape of the crack tip maung observation,the comprehensive analysis result showed that the tantalum rod ends of the lower density,and oxygen and higher nitrogen content,the surface of rip internal voids,inclusions,etc.,is caused by the rolling of the ends of the main reason for cracking.Tantalum dough sintering ends insufficient sintering impurity effect Poor impurity phase along the grain boundary precipitates easily weaken the bonding strength of the metal grain boundary,thereby reducing the plasticity of the metal susceptible to cracking upon impact,is the root cause.