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采用双步球磨法和放电等离子烧结(SPS)技术制备细晶Ti-47Al(at%)合金,利用扫描电子显微镜(SEM)、X射线衍射(XRD)仪以及透射电子显微镜(TEM)等分析测试手段对球磨后的粉末形貌结构、相组成以及烧结块体的显微组织结构进行观察和分析。结果表明:双步球磨粉末的颗粒形状较规则,其颗粒尺寸在20~40μm之间,内部结构均匀,主要由TiAl和Ti3Al相组成。放电等离子烧结后的块体主要由主相TiAl和少量的Ti3Al相及Ti2Al相组成,随着烧结温度的升高,Ti3Al相含量有所增加。当烧结温度为1000℃时,烧结块体获得的主要是等轴晶组织,等轴晶粒尺寸大多数在100~250nm之间。当烧结温度为1100℃时,烧结块体致密、无孔洞,等轴晶粒有明显长大的现象,显微组织主要由等轴状的TiAl相和片层状的Ti3Al相组成。
The fine-grained Ti-47Al (at%) alloy was prepared by two-step ball milling and spark plasma sintering (SPS). The microstructures were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM) Means the morphology of the powder after milling structure, phase composition and microstructure of the sintered block were observed and analyzed. The results show that the particle shape of the two-step ball-milling powder is more regular, the particle size is between 20μm and 40μm, and the internal structure is uniform. The particle size is mainly composed of TiAl and Ti3Al phases. After the discharge plasma sintering block mainly consists of the main phase TiAl and a small amount of Ti3Al phase and Ti2Al phase composition, with the sintering temperature increases, Ti3Al phase content increased. When the sintering temperature is 1000 ℃, the sintered block obtained mainly equiaxed grain structure, the majority of equiaxed grain size between 100 ~ 250nm. When the sintering temperature is 1100 ℃, the agglomerate is dense, non-porous and the equiaxed grains grow obviously. The microstructure consists of equiaxed TiAl phase and lamellar Ti3Al phase.