水力侵彻铝合金表面致损形态及粗糙度演化特征

为揭示水力侵彻铝合金致损形态及粗糙度演化特征,以提高水力加工铝合金表面质量及形态控制水平。提出了一种基于3D图像处理技术的非接触粗糙度表征方法,结合水力侵彻铝合金表面破坏形貌,研究了铝合金的区域性破坏机理,量化了各致损形态的动态演化过程;通过综合反映粗糙度多维参数指标,研究了水力侵彻铝合金表面粗糙度的分布及演化特征。研究结果表明:水力侵彻铝合金致损形态可分为断裂区,损伤形变区及塑性扩展区,侵彻面粗糙度沿射流径向整体呈"增-减-稳"的三阶演化趋势,粗糙度的离散性和波动性沿射流径向逐渐降低,粗糙度峰值与水力冲击时间有显著正相关性,水力持续冲击作用下侵彻面粗糙度分布概率的集中性呈渐增趋势。

The Damage Morphology and Surface Roughness Evolution Characteristic of Aluminum Alloy under Hydraulic Penetrating

To improve the surface quality and shape control level of hydraulic machining aluminum alloy, a non-contact roughness characterization method was proposed, by the 3D image processing technology. According to the damage morphology of aluminum alloy, it studied the regional failure mechanisms of aluminum alloy under hydraulic penetrating, and quantified the dynamic evolution processes in different damage regions. Then through the roughness multiple indicators, it addressed the surface roughness distribution and evolution characteristic of aluminum alloy by hydraulic penetrating. The results show that the damage morphology of aluminum alloy under hydraulic penetrating can be subdivided into the crack area, the damage deformation area and the plastic extension area. In the radial direction of the water jet, the surface roughness has three distinct change processes, including the increasing stage, decreasing stage and the stable stage, and the dispersion and volatility of the surface roughness decrease gradually. The peak roughness and the impacting time have a significant positive correlation. The concentration of the surface roughness distribution probability tends to be higher with the time.