激光与外载荷联合加载7075铝合金的实验研究  

Experimental study of 7075 aluminum alloy under laser and external loading

作　　者：陈伊铭 李泽文 唐杰 沈中华[1] CHEN Yiming;LI Zewen;TANG Jie;SHEN Zhonghua(School of Science,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学理学院,南京210094

出　　处：《激光技术》2023年第1期13-18,共6页Laser Technology

基　　金：国家自然科学基金资助项目(61605079);中央高校基本科研业务费专项资金资助项目(30919011262)。

摘　　要：为了研究7075铝合金在激光与外载荷联合加载下的失效行为,采用最大拉力50 kN的拉伸伺服试验机与工作波长为1070 nm的6 kW连续光纤激光系统对7075铝合金进行了不同预载荷与不同激光功率密度下的联合加载实验,获得了该材料的拉应力-时间曲线、温度-时间曲线、失效时间-功率密度曲线、失效温度-功率密度曲线等,分析了功率密度与预载荷对失效过程、失效温度和断裂形貌的影响。结果表明,在相同的预载荷下,激光功率密度的增大会导致失效时间非线性下降,失效温度是否有较大变化取决于预载荷的大小,当预载荷大(330 MPa, 440 MPa)时,失效温度随功率密度增加略有升高,预载荷较小(110 MPa, 220 MPa)时,失效温度变化规律不单调;在相同的激光功率密度下,预载荷增大,失效时间减少,功率密度较大、预载荷较小时,失效行为变得相似;在一定的功率密度(315 W/cm2,351 W/cm2)下,失效温度随预载荷的增大先增大后减小。该结果进一步揭示了7075铝合金的失效机理。In order to study the failure behavior of 7075 aluminum alloy under the combined loading of laser and external load, the joint loading experiments of 7075 aluminum alloy under different preloads and different laser power densities were carried out by using a tensile servo test machine with the maximum tension of 50 kN and a 6 kW continuous fiber laser system with the operating wavelength of 1070 nm. The tensile stress-time curve, temperature-time curve, fracture time-power density curve, and fracture temperature-power density curve were obtained. The effects of power density and preload on fracture process, fracture temperature, and fracture morphology were respectively analyzed. The results show that, under the same preload, the increase of laser power density leads to the nonlinear decline of fracture time, and the fracture temperature varies greatly depending on the size of preload. When the preload is large(330 MPa and 440 MPa), the fracture temperature increases slightly with the increase of power density, and when the preload is small(110 MPa and 220 MPa), the fracture temperature increases slightly with the increase of power density. Fracture temperature change rule is not monotonous, under the same laser power density, the fracture time decreases with the increase of preload, and the fracture behavior becomes similar with the increase of power density and the decrease of preload. At a certain power density(315 W/cm~2 and 351 W/cm~2), the fracture temperature increases first and then decreases with the increase of preload. The results further reveal the fracture mechanism of 7075 aluminum alloy.

关 键 词：激光技术 失效温度 失效时间 预载荷 7075铝合金 

分 类 号：TN249[电子电信—物理电子学] V261.8[航空宇航科学与技术—航空宇航制造工程]