电流对TC4钛合金高温压缩变形显微组织的影响

Effect of Current on Microstructure of TC4 Titanium Alloy during High Temperature Compression Deformation

摘要:

为研究电场作用下升温速度对TC4钛合金高温压缩变形显微组织的影响，利用Gleeble-1500D热-力学模拟机对原始晶粒尺寸为8和20 μm的TC4钛合金小圆柱体试样，分别以不同的升温速度加热至700 ℃进行了压缩实验。结果表明：电流作用下的高温压缩变形后，8 μm的TC4钛合金晶粒更细小，等轴性较变形前好；等轴α相增多，片层β相减少；等轴α相和片层β相的分布更均匀。20 μm的TC4钛合金在大电流和小电流作用下α相和β相中都出现了蜂窝状结构，且小电流作用下的蜂窝状结构比大电流作用下的蜂窝状结构明显。同等晶粒度下，电流越大，微观组织越均匀、晶粒越细小，等轴性越好

Abstract:

In order to study the effect of the heating rate on the microstructure of TC4 titanium alloy during high temperature compression deformation under the condition of electric field, cylinder samples with grain size of 8 μm and 20 μm were compressed with different heating rates at 700 oC using Gleeble-1500D thermal simulation instrument. The results show that grain size of 8 μm samples becomes finer and more equiaxial after high temperature compression deformation under the action of AC current, equiaxial α phase increases and flake β phase decreases. In addition, the distribution of equiaxial α phase and flake β phase becomes narrow. Both low current and high current heated TC4 titanium alloys of 20 μm have honeycomb structures, and honeycomb structures of low current heated TC4 titanium alloy is more pronounced. With the same grain size of TC4 titanium alloy, the higher the current, the finer the microstructure, and the more equiaxial.