ZTC4钛合金铸件表层与内部组织的相关性研究

Correlation between Surface and Internal Structures of ZTC4 Titanium Alloy Castings

采用组织定量分析技术,对某大型钛合金铸件产品各区域的组织进行定量评估,对比分析了铸件表层组织和内部组织的相关性,探讨了铸件本体组织评估中试样选取及观察原则。结果表明,铸件本体表层、中心层和截面获得的晶粒尺寸均值、晶粒尺寸分布半高宽均随铸件厚度增加呈线性增大的趋势,表层及中心层的晶粒尺寸分布相似并呈正态分布的特点,截面组织分布呈偏态分布的特点。结合钛合金铸件特点,在大型复杂精密钛合金铸件本体组织评估中,建议统一采用表层组织来评估铸件组织的均匀性。

Quantitative assessment techniques were employed to quantitatively evaluate the regional microstructure of some large titanium alloy castings,and the correlation between the surface and internal structures of castings was analyzed comparatively.The principle of sample selection and observation in the evaluation of the casting ontology was discussed.The results indicate that the average grain size and half-width of the grain size distribution obtained from the surface,central layer and cross section of the casting ontology are increased linearly with the thickness of the castings.The grain size of the surface and center layer are characterized by a normal distribution,while that of cross section is characterized by a skewed distribution.Combined with the characteristics of titanium alloy castings,it is recommended that the surface structure can be adopted to evaluate the uniformity of the casting structure in the evaluation of the casting ontology of large-scale complex precision titanium alloy.