7050铝合金的激光喷丸强度表征

分析了激光喷丸强度的表征机制,采用不同厚度的试片的弧高和表面残余应力对7050铝合金进行激光喷丸强度表征研究。弧高表征采用如下方法:试片冲击面尺寸(长×宽)为93 mm×10 mm,厚度分别为2.4、3.0、4.0、5.0 mm,吸收层采用铝箔,约束层采用流水,光斑的搭接率为30%,以激光作用在靶材的有效区域进行计算,夹持试片一端并采用U字形喷丸路径对试片中间规定区域进行喷丸。试验结果表明,激光喷丸强度可用试片弧高进行表征;不同厚度试片适合表征不同范围的激光喷丸强度,对于5～20 J的激光喷丸条件,选用2.4 mm试片较为合适;在能量为20～40 J激光喷丸条件下,4.0 mm试片应作为表征激光喷丸强度的优先选择;残余应力可以辅助试片弧高来表征激光喷丸强度。研究工作为7050铝合金激光喷丸强度表征提供了有效的方法,对激光喷丸质量控制具有重要的工程意义。

Laser peening intensity characterization of 7050 aluminum alloy

Mechanism of the laser peening intensity characterization was theoretically analyzed.The effect of the 7050 aluminum alloy laser peening intensity characterization was experimentally investigated based on arc height of the strips with different thicknesses and surface residual stress.Characterization method with arc height was as follows: the size of strips was 93 mm×10 mm,their thicknesses were 2.4,3.0,4.0,5.0 mm respectively.The overlap rate of laser spots was 30%,which was calculated with the effective area at the target.U shape laser peening path was used to process the specified area in the middle of the strip whose end was clamped.The results indicate that the laser peening intensity can be characterized by arc height of the strip;different range of laser peening intensity should be characterized by the strip with different thickness;residual stress can be used to assist arc height to characterize the laser peening intensity.2.4 mm strip is proper to characterize the laser peening intensity with the energy range from 5-20 J.4 mm strip should be the priority selection to characterize the laser peening intensity with the energy range from 20-40 J.Research provides an effective way for 7050 aluminum alloy laser peening intensity characterization,and it is of engineering significance for laser peening quality control.