The tribological behavior of tungsten carbide–cobalt materials is influenced by the cobalt content and the WC grains size. The main wear mechanisms in these materials are cobalt depletion, intergranular cracks, and WC grain cleavages. More specifically, coarse WC grains favor the apparition of transgranular cracks during sliding friction tests. A promising way to access in real-time blinded tribological contacts is the technique of acoustic emission (AE). This study clearly identifies transgranular cracks in AE signals. The AE energy and frequency of this mechanism were experimentally associated with the size of the transgranular cracks. A mechanical model based on the classical beam theory and harmonic motion equations confirms these relations. The AE centroid period (i.e., inverse of the centroid frequency) increases linearly with the size of the transgranular cracks. The AE energy increases linearly with the cube of the transgranular cracks length.

Graphical Abstract

中文翻译：

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WC-Co 硬质合金单向划痕过程中穿晶裂纹的声发射表征

碳化钨-钴材料的摩擦学行为受钴含量和 WC 晶粒尺寸的影响。这些材料的主要磨损机制是钴耗竭、晶间裂纹和 WC 晶粒解理。更具体地说，粗 WC 晶粒有利于在滑动摩擦试验中出现穿晶裂纹。一种有前途的实时盲摩擦接触方式是声发射 (AE) 技术。这项研究清楚地识别了 AE 信号中的穿晶裂纹。这种机制的 AE 能量和频率在实验上与穿晶裂纹的大小有关。基于经典梁理论和谐波运动方程的机械模型证实了这些关系。AE 质心周期（即 质心频率的倒数）随着穿晶裂纹的大小线性增加。AE 能量随着穿晶裂纹长度的立方线性增加。

图形概要