微量杂质在工业纯钛中的存在形式及其对力学性能的影响

摘要

The existence form and distribution of impurities (such as Fe, Si, Cl, N, O, C) in CP Ti and their effects on mechanical properties were investigated by DSC, XRD, EPMA and mechanical testing at room temperature. The results indicate that the contents of Fe, Si, Cl are low, only few areas exist segregation. The distribution of C is asymmetrical and there exists hugely segregation phenomenon. The content of O is fewer, and it is well-distributed. With the impurity content (Fe, Si, Cl, N, O, C and so on) increasing, the strength and hardness of CP Ti increase largely. Meanwhile, the plasticity and toughness decrease obviously. The largest increments of hardness,σ0.2,σb are 24 HB, 144 MPa and 122 MPa, respectively. While the largest decrease range of elongationis 19.8%.%采用差示扫描量热法(DSC)、X射线衍射(XRD)、扫描电镜及其附带的能谱仪(SEM+EDS)、电子探针(EPMA)等分析方法和力学性能测试，研究常温下铁、硅、氯、氮、氧、碳(Fe，Si，Cl，M，O，C)等杂质在工业纯钛中的存在形式、分布状况及其对力学性能的影响。结果表明：在工业纯钛中，铁、硅、氯杂质元素的微区元素浓度较低，只有极少区域存在偏聚；碳元素分布不均匀，微区偏聚现象明显；氧元素在工业纯钛中含量较少且分布均匀；随铁、氮、氧、碳、氯等杂质含量增加，工业纯钛的强度和硬度大幅提高，塑韧性显著降低，最大硬度 HB增幅为24，屈服强度和抗拉强度的最大增加幅度分别为144 MPa和122 MPa，伸长率的减幅最大为19.8%。