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采用连续变断面循环挤压对TC4钛合金进行变形,研究变形工艺参数对TC4合金沿径向显微组织及显微硬度的影响。结果表明,随着变形温度升高,α相尺寸虽然变化较小但还是有一定程度的长大;变形速度对显微组织中初生α相的含量影响较小,但对其形态和晶粒尺寸的影响相对较大:低速变形时,初生α相呈长条状,而以较高速度变形时,初生α相晶粒呈等轴状,且晶粒有一定程度细化,这是由于在该变形条件下发生了完全动态再结晶;随着变形道次的增加,晶粒细化程度增加,当试样经6道次循环挤压后组织细化效果显著,由原始尺寸的10μm细化至4μm。变形温度及变形速度对试样沿径向的显微硬度分布影响较小,但循环道次却对其影响较显著,随着循环道次的增加,试样沿径向显微硬度值较高且同一试样上的差异较小、分布较均匀,这与组织得到显著细化及均匀化有关。
The TC4 titanium alloy was deformed by continuous variable cross-section cyclic extrusion, and the effect of deformation parameters on the radial microstructure and microhardness of TC4 alloy was studied. The results show that with the increase of deformation temperature, the α phase size changes slightly but still has a certain degree of growth. The deformation rate has little effect on the primary α phase content in the microstructure. However, the morphology and grain size , The primary alpha phase is elongated, whereas at higher speeds the primary alpha phase grains are equiaxed and the grains are somewhat refined, The complete dynamic recrystallization occurred under the deformation conditions. With the increase of deformation pass, the degree of grain refinement increased. When the sample was pressed by 6 passes, the microstructure refinement effect was remarkable, from the original size of 10μm to 4μm. The deformation temperature and the deformation velocity have little influence on the radial microhardness distribution of the sample, but the circulation pass has a significant impact on it. With the increase of the circulation pass, the radial microhardness value of the sample is higher And the same sample on the smaller, more evenly distributed, which is significantly refined and homogenized organization.