论文部分内容阅读
本文研究了烧结态粉末冶金TZC钼合金(PM-TZC)的室温脆性和添加稀土元素La对烧结态PM-TZC合金显微组织及机械性能的影响。研究结果表明:PM-TZC合金存在室温脆性的主要原因是碳和氧在合金晶界处严重偏聚;适量La的加入可以改善PM-TZC合金的室温脆性,其主要原因是La的加人大大减弱了碳和氧的晶界偏聚,La在烧结态PM-TZC合金中主要以具有面心立方晶体结构的La_2Z的_2O_7复合氧化物形式存在,这种复合氧化物以稳定的球形小粒子弥散分布于合金中,并通过形成以该相为核心的球状共生相促进碳化物的形成,因而提高了合金的室温和高温强度及硬度。
In this paper, the room temperature brittleness and rare earth element La on the microstructure and mechanical properties of sintered PM-TZC alloy were studied. The results show that the room-temperature brittleness of PM-TZC alloy is mainly due to the severe segregation of C and O at the grain boundary. The addition of proper amount of La can improve the room-temperature brittleness of PM-TZC alloy, Weakens the grain boundary segregation of carbon and oxygen. La exists in the as-sintered PM-TZC alloy mainly as _2O_7 complex oxide of La_2Z with a face-centered cubic crystal structure, and this complex oxide takes the form of stable spherical small particles Dispersed in the alloy and promoted the formation of carbides by forming a spherical intergrown phase having the core as the core, thereby enhancing the room temperature and high temperature strength and hardness of the alloy.