Background

High-velocity oxy-fuel (HVOF)-sprayed metallic coating can be used to create a surface layer that plays a significant role in enhancing the overall strength, stiffness, and fatigue life of the treated material. The micro-deformation around a single impacted particle is a critical factor that must be considered for the optimization of the HVOF process.

Objective

In this study, the micro-deformation field of stainless steel impacted by a ceramic particle was characterized at the micro-scale.

Method

A grid with a frequency of 1200 lines/mm was fabricated on the surface of stainless steel specimen. The microscopic deformation field formed on the substreate surface, induced by the impact of micro-particles with a diameter of 18 µm, was determined using the electron moiré method and numerical simulations.

Results

The in-plane plastic strain around the impacted particle was found to be as high as 9.1%, and the value sharply decreased with the increase of the distance to the edge of the impacted particle. The diameter of the plastic area was about 40 µm, which was approximately 2.2 times larger than the particle size. The experimental results were compared with numerical simulation results, and good agreement between the results was found.

Conclusions

The electron moiré technique can be a useful tool for the measurement of the deformation field induced by an impacted particle in a very local area with a size on the order of microns.

中文翻译：

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用电子莫尔条纹法研究陶瓷颗粒对不锈钢的微变形影响

背景

可以使用高速喷涂的含氧燃料（HVOF）喷涂的金属涂层来形成表面层，该表面层在提高被处理材料的整体强度，刚度和疲劳寿命方面起着重要作用。单个撞击粒子周围的微变形是优化HVOF工艺必须考虑的关键因素。

客观的

在这项研究中，在微观尺度上表征了受陶瓷颗粒影响的不锈钢的微形变场。

方法

在不锈钢试样的表面上制作了频率为1200线/ mm的网格。使用电子莫尔条纹法和数值模拟确定了由直径为18 µm的微粒的撞击所引起的在底物表面上形成的微观形变场。

结果

发现冲击颗粒周围的面内塑性应变高达9.1％，并且该值随着到冲击颗粒边缘的距离的增加而急剧下降。塑料区域的直径约为40 µm，约为粒径的2.2倍。将实验结果与数值模拟结果进行了比较，发现两者之间具有很好的一致性。

结论

电子莫尔条纹技术可能是一种有用的工具，可用于测量尺寸非常大的局部区域中受撞击粒子引起的形变场。