不同速率变形后WE54合金的显微组织及力学性能

Microstructure and Mechanical Properties of WE54 Alloy after Deformation under Different Speeds

对T4态和T6态WE54合金进行准静态压缩变形和空气锤锻(高速)变形试验,研究了变形前后的显微组织、硬度和压缩性能。结果表明:T4态和T6态WE54合金在准静态变形和高速变形后,部分变形晶粒内出现孪晶,并且在一些粗大孪晶内形成了二次孪晶,孪晶出现平行排列和交割特征;不同速率变形后T4态和T6态合金的变形晶粒尺寸未发生明显变化,但新生成的孪晶由于切割基体细化了组织,有助于维氏硬度和压缩性能的提高;与准静态变形相比,高速变形能够促进晶粒采用孪生机制协调变形,产生更多的孪晶界细化组织,提升变形后合金的硬度和屈服强度。

The WE54 alloy in T4 and T6 states were deformed by quasi-static compression and air-hammer forging(high speed). The microstructures, hardness and compression performance before and after deformation were investigated. The results show that after the quasi-static deformation and high speed deformation, twins appeared in some deformed grains of WE54 alloys in T4 and T6 states, and secondary twins were fomed in some coarse twins. These twins exhibited parallel arrangement or intersection features. The deformed grain size remained invariable in the T4 and T6 alloys after deformation at different speeds, but the refining structure due to the sectioning of matrix by newly formed twins was helpful for the improvement of Vickers hardness and compression performence. Compared with the quasi-static compression, the high speed deformation promoted the twinning mechanism to coordinate deformation, therefore induced more twin boundaries to refine the matrix and enhance the hardness and yield strength of the deformed alloys.