基于模具分区预热的TA1等通道挤压工艺研究  

Research on TA1 Equal-channel Extrusion Process Based on Die Zone Preheating

作　　者：赵军 徐浩杰 贾宾 牛轻松 罗枢源 ZHAO Jun;XU Haojie;JIA Bin;NIU Qingsong;LUO Shuyuan(School of Materials Science and Engineering,Xiamen University of Technology,Xiamen 361024,China)

机构地区：[1]厦门理工学院材料科学与工程学院,福建厦门361024

出　　处：《热加工工艺》2024年第24期34-38,47,共6页Hot Working Technology

基　　金：厦门市自然科学基金项目(3502Z20227222)。

摘　　要：在钛合金等通道挤压成形过程中,由于钛合金变形温度范围窄,要对模具进行较高温度的预热,以减小坯料温度下降对变形过程的影响。为减小模具温度对成形过程以及模具受热膨胀变形的影响,提出了模具分区预热的方法,设计了三因素四水平的正交试验,使用极差分析对16组正交方案进行了分析,优化了模具分区预热方案。对比分析了模具380℃预热与分区预热(变形区380℃+其它区150℃)对成形载荷、坯料应力应变、模具的热膨胀、坯料成形效果以及微观组织的影响。结果表明:采用模具分区预热后,材料等效应变由2.76下降为2.44;等效应力由379 MPa下降为352MPa;挤出后坯料温度为316℃,下降了38℃;成形载荷下降了2.9 kN,最大为24.6 kN;模具最大膨胀较整体预热减小了0.30 mm,变形区膨胀减小了0.15 mm。分区加热后成形效果更加优越,晶粒尺寸细化更加明显,约为5μm。Due to the narrow deformation temperature range of titanium alloy in the process of equal channel extrusion forming,it is often necessary to preheat the die at a higher temperature so as to reduce the influence of the billet temperature drop on the deformation process.In order to reduce the influence of mold temperature on the forming process and the deformation of the mold by thermal expansion,the method of zonal preheating of the mold was proposed,and a three-factor four-level orthogonal experiment was designed,and 16 groups of orthogonal schemes were analyzed using polar analysis to optimize the zonal preheating scheme of the mold.The influences of the 380℃preheating and zone preheating(deformation zone 380℃+other zones 150℃)of the mold on forming load,billet stress and strain,thermal expansion of the mold,billet forming effect and microstructure were compared and analyzed.The results show that the equivalent strain of the material decreases from 2.76 to 2.44 after zonal preheating of the die,the equivalent stress decreases from 379 MPa to 352 MPa;the temperature of the billet after extrusion is 316℃,which decreases by 38℃.The forming load decreases by 2.9 kN,and the maximum is 24.6 kN;the maximum expansion of the mold decreases by 0.30 mm compared with that of the overall preheating,and the expansion of the deformation zone decreases by 0.15 mm.The forming effect after zonal heating is more superior,and the grain size refinement is more obvious,which is about 5μm.

关 键 词：TA1 等通道挤压 温度 正交试验 模具分区 

分 类 号：TG316[金属学及工艺—金属压力加工]