低频振动模式下紫铜压缩变形行为及尺寸效应  

Compression deformation behavior and size effect of copper under low-frequency vibration

作　　者：李盼[1] 王新云[1] 张茂[1] 邓磊[1] 金俊松[1] 夏巨谌[1] 

机构地区：[1]华中科技大学材料成形与模具技术国家重点实验室,湖北武汉430074

出　　处：《锻压技术》2017年第8期140-145,共6页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(51175202);湖北省科技支撑计划项目(2015BAA019);深圳市基础研究计划项目(201605313001169)

摘　　要：通过改变低频振动加载条件,研究了振幅(0.01,0.05和0.1 mm)、频率(10,20和30 Hz)、进给速率(0.01,0.05和0.1 mm·s^(-1))和试样尺寸(Ф1,Ф2和Ф3 mm)对T2紫铜室温压缩变形行为的影响。实验结果表明,振幅对紫铜压缩变形过程的影响最为显著,随着振幅增加,成形载荷呈现较大幅度的降低;不同尺寸试样的实验结果表明,低频振动加载模式下存在明显的尺寸效应,随着试样尺寸减小,成形载荷降幅增大,晶粒尺寸减小。分析认为,振动条件下的变形为动态加载变形,应力的叠加使得内应力提高,并导致所需成形载荷降低。大振幅和小尺寸条件下,实际应变速率更大,能够产生更强的应力叠加,造成成形载荷降幅较大。The influences of amplitude（ 0. 01,0. 05 and 0. 1 mm）,frequency（ 10,20 and 30 Hz）,feeding rate（ 0. 01,0. 05 and0. 1 mm·s^（-1）） and specimen size（ Ф1,Ф2 and Ф3 mm） on the room-temperature compression deformation behavior of copper T2 were experimentally investigated by changing low-frequency vibration loading. The results reveal that the vibration amplitude plays the most significant role in the compression deformation of copper,and the forming load is effectively reduced with the increase of vibration amplitude. It also shows strong evidence of size effects during low-frequency vibration loading by experiment of different specimen sizes. The smaller the sample size is,the greater the forming load reduces and the smaller the grain size is. It is concluded that the deformation under vibration condition is dynamic loading,and the superposition of stress leads to the increase of internal stress and the reduction of required forming load. Under the condition of large amplitude or small size,the actual strain rate becomes greater,which enhances the superposition of stress and reduces forming load greatly.

关 键 词：低频振动 压缩变形 T2紫铜 尺寸效应 应力叠加 晶粒细化 

分 类 号：TG146.11[一般工业技术—材料科学与工程]