7075铝合金低应力多冲碰撞塑性变形动态响应  

Dynamic response on plastic deformation of 7075 aluminium alloy under low stress and multi-impact

作　　者：黄晓华[1,2] 傅戈雁[2] 杨强[3] Huang Xiaohua;Fu Geyan;Yang Qiang(College of Precision Manufacturing,Suzhou Vocational Institute of Industrial Technology,Suzhou 215104,China;College of Mechanical and Electrical Engineering,Soochow University,Suzhou 215021,China;Aircraft Strength Research Institute of China,Xi'an 710065,China)

机构地区：[1]苏州工业职业技术学院精密制造学院,江苏苏州215104 [2]苏州大学机电工程学院,江苏苏州215021 [3]中国飞机强度研究所,陕西西安710065

出　　处：《锻压技术》2024年第9期230-238,共9页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(K111709416);江苏省高校基础科学研究重大项目(23KJA460012);苏州工业职业技术学院科研创新团队项目(2021KYTD001)。

摘　　要：在338.1、382.3和433.6 MPa冲击应力下,使用0.25、1.00、2.00和4.00 Hz的冲击频率对7075铝合金试样进行多冲碰撞试验,利用图像处理软件测量试样的累积塑性变形量和各层深值的变化,根据试验数据建立了S-σ-f-N的数学关系,并且通过金相显微组织分析晶粒变化。试验结果表明:试样的变形与冲击应力、冲击频率和冲击次数的大小有关,且均呈正相关,材料动态变形规律具有趋表效应,冲击频率逐级增大,形变增量梯度逐级衰减;当其他冲击条件相同时,冲击应力增大到一定值,约为7075铝合金材料的屈服强度的95.3%时,材料显微组织呈现纤维状。对比各项冲击因素,冲击应力是影响7075铝合金材料塑性变形的主要因素。Under the impact stresses of 338.1,382.3 and 433.6 MPa,the multi-impact test on 7075 aluminum alloy specimen was conducted using the impact frequencies of 0.25,1.00,2.00 and 4.00 Hz,and the cumulative plastic deformation and the depth change of each layer for specimen were measured by image processing software.Then,based on the experimental data,the mathematical relationship of s-σ-f-N was established,and the grain change was analyzed by metallographic microstructure.The experimental results show that the deformation of specimen is related to impact stress,impact frequency and impact times,and they are all positively correlated.The dynamic deformation law of materials has the effect of tending to the surface.With the increasing of the impact frequency step by step,the deformation increment gradient decreases step by step.When the other impact conditions are the same,the impact stress increases to a certain value,about 95.3% yield strength of 7075 aluminium alloy,and the microstructure of material appears fibrous.Thus,comparing various impact factors,the impact stress is the main factor that affects the plastic deformation of 7075 aluminum alloy.

关 键 词：低应力多冲碰撞 累积塑性变形 冲击频率 冲击应力 显微组织 

分 类 号：TG146.21[一般工业技术—材料科学与工程]