Microstructural Evolution and Mechanical Properties of a Vanadium and Yttrium TiAl Based Alloy Densified by Spark Plasma Sintering
Titanium aluminum alloys are a new class of lightweight structural materials with high-temperature mechanical properties.However,owing to its poor casting and machining performance,the practical application of Ti-Al intermetallic is seriously constrained.Instead,powder metallurgy can be a fundamental solution to these problems.And as a unique kind of powder metallurgy techniques,spark plasma sintering(SPS)can be used to produce refined microstructure since it offers rapid heating and cooling rates.In this work,a vanadium and yttrium containing alloying powders(Ti-43Al-9V-0.3Y)were fabricated by gas atomization process and then consolidated by spark plasma sintering(SPS)at temperatures between 950 and 1250℃.Microstructures of sintered alloys are analyzed by scanning and transmission electron microscopies.When the sintering temperature is 950℃,the dendritic structure in the gas-atomized powder particles is fully recrystallized and it consists of refined γ(TiAl),B2 grains and fine dispersed YAl2 particles,but several original powder particle boundaries still remained.Specimens sintered at 1100℃ and 1150℃ are characterized by uniform duplex microstructure,the fine YAl2 particles are still dispersedly distributed in the matrix.While the SPS temperatures above 1200℃,fully-lamellar(FL)microstructure emerged and the majority of γ/α2 colonies are typical strip-like.Specimens sintered at 1100℃ has best mechanical properties with a tensile strength of 981 MPa,yield strength of 833MPa and a good elongation of 2.35%at room temperature.It is remarkable that the SPSed specimens with sintering temperature from 1100 to 1200℃ all have good integrated mechanical properties.
Powder metallurgy TiAl Mechanical properties Transmission electron microscopy
Gu Xu Cao Fuyang Zhang Dongdong Liu Na Shen Hongxian Sun Jianfei
School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China Science and Technology on Advanced High Temperature Structural Materials Laboratory,Beijing Institut
国际会议
北京
英文
519-525
2018-09-16（万方平台首次上网日期，不代表论文的发表时间）