摘要
在热模拟试验机上对TC21钛合金进行了等温恒应变速率压缩试验,利用获得的流动应力数据计算了不同变形条件下的lnZ、变形激活能Q和功率耗散效率η,建立了这些参数对变形温度、应变速率和应变的响应面模型。绘制出lnZ、Q和η对变形温度、应变速率和应变之间交互作用的响应曲面,分析了lnZ、Q和η随这些热变形参数之间交互作用的变化规律,通过追求最低的Q值和lnZ值以及最高的η值对热变形参数进行了多目标可视化优化。结果表明,lnZ和Q随应变速率的降低而减小,η随应变速率的降低而增大,三者均随变形温度的增加先增大后减小。所建立的响应面模型具有较高的精度,利用该模型优化的热变形参数范围为860~900℃、0.001~0.002 s^(-1),最佳变形条件为877℃、0.001 s^(-1),在该变形条件附近加工可获得球化分数较高、尺寸较小的等轴组织。
The isothermal compression tests for TC21 titanium alloy with lamellar microstructure were carried out at constant strain rates on hot working simulator.The obtained flow stress data was utilized to calculate the lnZ,deformation activation energy Q and power dissipation efficiencyηunder different deformation conditions,and the response surface models of parameters to deformation temperature,strain rate and strain were established.The response surfaces of lnZ,Q andηto the interaction between deformation temperature,strain rate and strain were plotted,and the variation law of lnZ,Q andηwith the interaction between these hot deformation parameters were analyzed.By pursuing the lowest Q and Z values and the highestηvalue,the hot deformation parameters were optimized by multi-objective visualization.The results indicate that with strain rate decrease,the values of lnZ and Q are decreased and the value ofηis increased,while all parameters are increased firstly and then decreased with deformation temperature increase.The established response surface model possesses high accuracy,and the range of hot deformation parameters optimized by the model is 860~900℃,0.001~0.002 s^(-1).The optimal deformation condition is 877℃and 0.001 s^(-1),where the equiaxial microstructure with higher spheroidization fraction and smaller size can be achieved.
作者
李鑫
张开铭
王克鲁
鲁世强
Li Xin;Zhang Kaiming;Wang Kelu;Lu Shiqiang(School of Aerospace Manufacturing Engineering,Nanchang Hangkong University)
出处
《特种铸造及有色合金》
CAS
北大核心
2023年第11期1478-1484,共7页
Special Casting & Nonferrous Alloys
基金
国家自然科学基金资助项目(51864035)
江西省自然科学基金资助项目(20202ACBL204001)。
关键词
TC21钛合金
响应面法
微观组织
TC21 Titanium Alloy
Response Surface Methodology
Microstructure
