电液颤振对冷挤压塑性成形件金属流线及晶粒组织的影响  

Impacts of Electro-hydraulic Vibration Applied in Cold Extrusion of Metal Plastic Forming Process on Metal Flow Lines and Grain Structure

作　　者：杨庆华[1] 洪潇潇[1] 王志恒[1] 鲍官军[1] 胡新华[1] 薛军义 

机构地区：[1]浙江工业大学特种装备制造与先进加工技术教育部/浙江省重点实验室,杭州310032

出　　处：《中国机械工程》2015年第16期2226-2232,共7页China Mechanical Engineering

基　　金：国家自然科学基金资助项目(51275475);特种装备制造与先进加工技术教育部/浙江省重点实验室开放基金资助项目(2014EP0110)

摘　　要：针对冷挤压成形过程中金属变形抗力大、模具易磨损等不足,提出一种新型冷挤压工艺,即在冷挤压成形过程中引入振动激励信号。运用 DEFORM-3D 有限元分析软件构建系统仿真模型,分别在有无施加颤振两种挤压方式下进行模拟仿真。仿真结果表明,施加颤振信号能促进金属的流动,金属流动速度达到62.4 mm/s,网格流线变形程度比传统挤压方式下的变形程度小。设计了电液式颤振冷挤压实验平台及模具,分别在有无施加颤振两种挤压方式下进行实验,并将所得成形零件用体积分数为4%的硝酸酒精溶液腐蚀,利用扫描电镜观察零件剖面。实验结果表明,施加颤振信号后,晶粒由原来的大小为3.3-5.0μm 细化到1.7-3.3μm,晶粒变形更加均匀,变形组织更加细密,金属纤维组织变得更细更长。Cold extrusion process had some disadvantages,such as gigantic metal deformation re-sistance,mold wear,etc.a new type of cold extrusion process was proposed,where vibration excitation signals were applied in the cold extrusion process.Using DEFORM-3D finite element analysis soft-ware,the system simulation models were built and the forming process was simulated on whether the vibration was applied to this process.Simulation results show that the signal can be applied to facili-tate the metal flow,and the metal flow rate reaches 62.4 mm/s.The degree of deformation of the mesh flow lines is smaller than that in the condition of traditional squeeze mode.A kind of electro-hy-draulic vibration experimental platform and die were designed for this project.Experiments were com-pleted on the conditions of whether the vibration was applied to this process.Etching molded parts with 4% Nital,and SEM was used to observe the part sections.Experimental results show that after the application of vibration signals in cold extrusion,the grain size reduce from about 3.3 -5.0μm to 1.7 3.3 μm,grain deformation becomes more uniform,deformation tissue becomes more dense,me-tallic fibrous tissue becomes finer and longer.

关 键 词：冷挤压 有限元模拟 金属塑性成形 电液颤振 金属流线 

分 类 号：TG14[一般工业技术—材料科学与工程]