预加载条件下钛合金锥形压痕代表应变的确定  

Determination of representative strain of titanium alloy induced by sharp indentation under pre-load condition

作　　者：吉喆[1] 高二庆 沈承金[1] 宋庆雷 徐杰[1] 郭涛 JI Zhe;GAO Er-qing;SHEN Cheng-jin;SONG Qing-lei;XU Jie;GUO Tao(School of Material Science and Engineering,China University of Mining and Technology,Xuzhou 221116,China;Xuzhou BUT Construction Machinery Joint-stock Co.,Ltd.,Xuzhou 221004,China)

机构地区：[1]中国矿业大学材料科学与工程学院,江苏徐州221116 [2]徐州巴特工程机械股份有限公司,江苏徐州221004

出　　处：《塑性工程学报》2019年第4期213-219,共7页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(51505481)

摘　　要：为通过锥形压痕代表应变和约束因子反求钛合金的应力-应变曲线,建立了预加载条件下的压痕变形有限元模型,使用预加载压痕实验的载荷-位移曲线验证了模型的可靠性。通过有限元模型研究了Ti-6.5Al-3.5Mo-1.5Zr-0.3Si(TC11)合金力学性能与代表应变和约束因子的关系。结果表明,TC11合金硬度与强度系数比值的自然对数与预应变和代表应变之和的自然对数呈线性关系。TC11合金代表应变范围为0.035~0.05,对应的约束因子的变化范围为3.08~3.42。代表应变和约束因子的值随合金性能变化而变化,并不存在固定的值。代表应变随着压痕塑性变形区平均应变增加而增加。由本方法确定的压痕代表应变和约束因子计算的代表应力与TC11合金应力-应变曲线重合良好。To calculate the stress-strain curve of titanium alloy by representative strain and constraint factor induced by sharp indentation,the finite element model of indentation process under pre-load condition was established,the reliability of the model was verified by the load-displacement curve of the pre-load indentation test.The relationship between mechanical properties of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si(TC11)alloy,representative strain and constraint factor was studied by the established model.The results show that linear relationship is between natural logarithm of the ratio of hardness and strength coefficient of TC11 alloy and natural logarithm of the sum of pre-strain and representative strain.The representative strain range of the alloy is 0.035-0.05 and constraint factor range is 3.08-3.42.Representa-tive strain and constraint factor vary with the mechanical properties of TC11 alloy,and there is no fixed value.Representative strain in-creases with the average strain in plastic strain region under the indenter.The indentation representative strain determined by this method and the representative stress calculated by constraint factor coincide well with the stress-strain curve of TC11 alloy.

关 键 词：钛合金 代表应变 有限元分析 压痕测试 

分 类 号：TG146.2[一般工业技术—材料科学与工程]