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利用放电等离子烧结技术制备了一种低成本车用钛合金(Ti-4.3Fe-7.1Cr-3Al),研究烧结温度对其晶粒尺寸、孔隙率、显微组织、成分均匀性、相结构及力学性能的影响。结果表明,在1100和1300℃两种烧结温度下,其显微组织基本由针状α相和β基体相组成,其间分布着条状或颗粒状TiC。随着烧结温度的升高,晶粒尺寸逐渐增大,孔隙率逐渐减小,TiC析出密度逐渐增多,针状α相逐渐减少,并且由1100℃的不均匀分布逐渐转变为1300℃的均匀分布。电子探针分析表明,1100℃时成分均匀性差,出现了Cr和Al元素的偏析,而1300℃时基本无偏析。XRD分析和纳米力学探针测量显示,添加的合金元素使β相的晶格参数减小以及细小第二相析出,弹性模量增大。
A low-cost automotive titanium alloy (Ti-4.3Fe-7.1Cr-3Al) was prepared by spark plasma sintering. The effects of sintering temperature on the grain size, porosity, microstructure, composition uniformity, Effect of mechanical properties. The results show that at 1100 and 1300 ℃ sintering temperature, the microstructure consists of acicular α-phase and β-base phase with strip or granular TiC distributed. With the increase of sintering temperature, the grain size gradually increases and the porosity decreases. The precipitation density of TiC gradually increases and the acicular α phase decreases gradually, and gradually changes from the non-uniform distribution of 1100 ℃ to the uniform distribution of 1300 ℃ . Electron probe analysis showed that the compositional homogeneity was poor at 1100 ℃, segregation of Cr and Al elements appeared, but no segregation at 1300 ℃. XRD analysis and nano-mechanical probe measurements show that the addition of alloying elements decreases the lattice parameter of β-phase and the precipitation of fine second phase, and the elastic modulus increases.