退火处理对TiZrAlV合金组织与力学性能的影响

Effect of annealing treatment on microstructure and mechanical properties of TiZrAlV alloy

采用X射线衍射仪、光学显微镜、扫描电镜、硬度测试和拉伸试验等方法研究退火处理对TiZrAlV合金的显微组织和力学性能的影响。结果表明：锻造态TiZrAlV合金由α相、β相以及少量fcc相组成;退火处理后,合金发生α＋β＋fcc→α＋β的相变过程,并且β相含量随退火温度升高而增加;TiZrAlV合金锻造态和退火态的微观组织特点为典型的网篮组织,并且随着退火温度的升高,α相片层的厚度逐渐增大;锻造态TiZrAlV合金的屈服强度、最大抗拉强度、伸长率以及硬度分别为833、955 MPa、13.08%以及36.5 HRC;退火处理后合金的屈服强度得到提升,400℃退火的屈服强度为982 MPa,抗拉强度为1136 MPa,而伸长率和硬度变化不大;退火处理后合金的拉伸断口由大量大小不等的韧窝组成,呈现塑性断裂特征。

The effect of annealing treatment on microstructure and mechanical properties of TiZrAlV alloy was studied by means of X-ray diffraction,optical microscope,scanning electrical microscopy,Rockwell hardness test and tensile test. The results show that the microstructure of the forged TiZrAlV alloy is composed of α phase,β phase and a small amount of fcc phase. After annealing treatment,the phase transformation process of α ＋ β ＋ fcc → α ＋ β occurs,and the volume fraction of β phase increases with the increasing of annealing temperature. The microstructure characteristic of the forged and annealed samples is typical basket-weave microstructure,and the thickness of α phase increases gradually with the increasing of annealing temperature. The yield strength,ultimate tensile strength,elongation and the Rockwell hardness of the forged sample are 833 MPa,955 MPa,13. 08%,and 36. 5 HRC,respectively. After annealing treatment,the yield strength of the alloy is improved,and the elongation and hardness change little,when annealed at 400 ℃,the yield strength and ultimate tensile strength of the alloy are 982 MPa and 1136 MPa,respectively. The tensile fracture of the alloy annealed at different temperatures is composed of a large number of dimples with different sizes,showing plastic fracture.