金属型离心铸造TiAl基合金耐磨性研究

Wear-resistance of Metallic Mold Centrifugal Casting TiAl Based Alloy

利用金属型离心铸造的方法,浇注了目标成分为Ti-48Al-2Cr-2Nb的合金,随后对其进行热等静压(HIP)处理1270℃/173 MPa/4h),研究了TiAl基合金的耐磨性能。研究结果表明,在载荷为50N、加载10min和载荷为100N、加载5min时,铸态样品的摩擦因数约为0.141;TiAl基合金经热等静压处理后,在载荷为50N、加载10min和载荷为100N、加载3min时,材料的摩擦因数为0.156。通过显微组织观察发现,HIP工艺对TiAl基合金摩擦因数的影响可归结为两方面:一是消除了铸件内部的微小缩松,提高了材料的致密度;二是组织结构由全片层向双态结构的转变。

Wear-resistance of Ti-48Al-2Cr-2Nb prepared by metallic mold centrifugal casting was tested in the conditions of casting and hot isostatic press (1 270 ℃/173 MPa/4 h). Experimental results reveal that the friction coefficient of as-cast samples is bout 0.140 with loading of 50 N for 10 min or loading of 100 N for 5min, while the friction coefficient of HIP treated alloy sample is about 0.158 with loading of 50 N for 10 min or loading of 100 N for 3 min. The microstructural observation indicates that the influence of HIP on friction coefficient of TiAl based alloy is attributed to eliminating shrinkage porosity in the samples to improve the compactness of the alloy and to convert the structure of the alloy from full laminar into duplex-structure.