论文部分内容阅读
本文对硬态铍青铜(QBe2)的超塑性力学行为和组织变化进行了研究。合金在温度为450～640℃和应变速率为1.95×10~(-4)～1.67×10~(-2)S~(-1)的范围内拉伸,能呈现较好的超塑性效应。当合金在550℃下以1.95×10~(-4)S~(-1)的应变速率拉伸时,延伸率可达780％。在较低的应变速率下拉伸。合金具有各向异性。在550℃下以8.33×10~(-4)S~(-1)的应变速率拉伸时,拉伸方向与原材料轧制方向成0°、45°和90°角的试样,延伸率分别为550％、860％和675％。而在较高的应变速率下拉伸,这种塑性差异消失。合金不需预先处理便可进行超塑性变形,通过动态再结晶使原始形变组织转化为微细等轴晶粒,同时利用第二相粒子对晶界的钉扎来控制晶拉粗化。拉伸后的试样在光学显微镜下观察未发现空洞,但试样的断裂却是由空洞的连接所致。
In this paper, the superplasticity behavior and microstructure of hard beryllium bronze (QBe2) were studied. The alloy shows good superplasticity at tensile stress of 450-640 ℃ and strain rate of 1.95 × 10 -4 -4.67 × 10 -2 S -1. When the alloy is stretched at a strain rate of 1.95 × 10 ~ (-4) S -1 at 550 ℃, the elongation can reach 780%. Stretch at lower strain rates. Alloy anisotropy. When the sample was stretched at a strain rate of 8.33 × 10 -4 S -1 at 550 ° C, the specimens whose tensile direction was at 0 °, 45 ° and 90 ° from the rolling direction of the raw material, the elongation Respectively 550%, 860% and 675%. At higher strain rates, this difference in plasticity disappears. The alloy can be superplastic deformation without prior treatment, through the dynamic recrystallization of the original deformed tissue into fine equiaxed grains, while the use of second phase grain pinning the grain boundary to control the coarsening of the crystal. After stretching the sample was observed under a light microscope no voids, but the sample is broken due to the hollow connection.