摘要
采用复合热机械处理工艺细化了Ti-Al-Nb-W-B合金铸态近片层组织,根据Ti-Al二元相图对合金组织形貌演变及生长机理进行了研究。结果表明,热等静压处理后的Ti-Al-Nb-W-B合金是由大量粗大α2/γ片层团晶粒和少量分布于片层团间的等轴γ晶粒以及B2相等组成,晶粒尺寸约为100μm;通过总变形量大于80%的复合锻造后,可得到表面平整光洁的饼材,其原始铸态的粗大片层状组织被明显细化,由偏析形成的β相经后续热处理可基本消除,并得到均匀细小的双态组织;合金经复合热机械处理后,室温拉伸塑性得到明显提高。
The as-cast nearly lamellar microstructure of Ti-Al-Nb-W-B alloy was refined by multi-step thermal mechanical treatment. The microstructure evolution and growth mechanism of the alloy were studied based on Ti-Al binary phase diagram. The results show that Ti-Al-Nb-W-B alloy is composed of large coarse α2/γ lamellar structures with a colony size of about 100μm and small amount of y and B2 phase after HIP. After multi-step forging with a total deformation of more than 80%, the pancake piece with smooth surface can be obtained, the as-cast nearly lamellar structure has been refined obviously and the β phase caused by segregation is mostly eliminated after heat treatment, and the homogeneous and fineduplex microstructure can be obtained. The ductility of this alloy at room temperature after multi-step thermal mechanical treatment has been improved significantly.
出处
《金属热处理》
EI
CAS
CSCD
北大核心
2007年第10期1-5,共5页
Heat Treatment of Metals
