一种新型Ti-Al-Mn-W合金组织与力学性能  

Microstructure and Mechanical Properties of Novel Ti-Al-Mn-W Alloy

作　　者：李小兵 舒磊 潜坤 陈波 薛鹏 张孟殊 刘奎 Li Xiaobing;Shu Lei;Qian Kun;Chen Bo;Xue Peng;Zhang Mengshu;Liu Kui(Ji Hua Laboratory,Foshan 528200,China)

机构地区：[1]季华实验室,广东佛山528200

出　　处：《稀有金属材料与工程》2023年第5期1851-1860,共10页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51971215);季华实验室科研项目(X210291TL210)。

摘　　要：设计并制备了一种新型低成本、易热变形的Ti-43Al-3.5Mn-0.5W(at%)合金锻锭,并对其组织、室/高温拉伸力学性能、抗高温氧化性、热变形能力进行了系统分析。结果表明,与Ti-42Al-5Mn相比,研制的合金强度、抗高温氧化性、热变形能力更佳,且该合金α2和βo相中具有更低的Mn含量,降低了合金近服役温度下富锰Laves相的析出倾向。合金的固态相变路线为:β→β+α→β+α+γ→β+βo+α+α2+γ→βo+α2+γ,其中γ相完全溶解的温度(T_(γ-solv))约为1250℃,β单相区温度(Tβ或Tα)约为1360℃。锻态合金显微组织为α2/γ片层和片层界面处大量βo和γ混合相,高温强度降低明显。通过两步热处理,锻态合金的高温强度和稳定性均有一定提升,这主要归结为片层组织含量的提高和片层晶团尺寸的细化。1260℃/0.5 h/AC+800℃/3 h/FC热处理合金800℃的屈服强度、抗拉强度和延伸率分别为320 MPa、555 MPa、16%。A novel thermal-deformable Ti-43Al-3.5Mn-0.5W(at%)alloy was designed and fabricated.The microstructure characterization,room and elevated temperature tensile mechanical properties,oxidation resistance,and deformation capacity of the alloy were investigated.The results indicate that compared with Ti-42Al-5Mn,the developed alloy has better strength,high temperature oxidation resistance and thermal deformation ability.Theα2 andβo phases of the alloy have lower Mn content,which reduces the precipitation tendency of Mn-rich Laves phase near the service temperature.The evolution of the phases in the alloy can be generalized as follows:β→β+α→β+α+γ→β+βo+α+α2+γ→βo+α2+γ,with the T_(γ-solv)≈1250℃,Tβ≈1360℃.The microstructure of the forged alloy is lamellar structure and a large number ofβo andγmixed phases at the lamellar interface.The high temperature strength of the forged alloy decreases obviously.Through two-step heat treatment,the high temperature strength and stability of the forged alloy are improved to a certain extent,which is mainly attributed to the increase in lamellar structure content and the refinement size of lamellar colonies.At 800℃,the yield strength,tensile strength,and elongation of the forged alloy treated with 1260℃/0.5 h/AC+800℃/3 h/FC were 320 MPa,555 MPa,and 16%,respectively.

关 键 词：β凝固γ-TiAl合金 组织 力学性能 锻造 

分 类 号：TG146.23[一般工业技术—材料科学与工程]