【Domestic Papers】Abrasive machining induced surface layer damage behavior and formation mechanism of monocrystalline β-Ga₂O₃: A comparative study of nanoindentation and nanogrinding

      Researchers from the Dalian University of Technology have published a dissertation titled " Abrasive machining induced surface layer damage behavior and formation mechanism of monocrystalline β-Ga₂O₃: A comparative study of nanoindentation and nanogrinding " in Materials Characterization.

Abstract

      Beta-phase gallium oxide (β-Ga₂O₃) has garnered significant attention in recent years as an ultra-wide bandgap semiconductor material. However, its surface layer damage behavior and machining deformation mechanism remain poorly understood. In this work, a systematic comparative study was conducted through nanoindentation and nanogrinding for monocrystalline β-Ga₂O₃ (−201) crystal plane. Transmission electron microscopy is employed as the primary characterization method. The results show that the microstructural evolution patterns of monocrystalline β-Ga₂O₃ can be categorized into four stages, i.e. stacking faults, twins, slip bands, and cleavage cracks are observed sequentially. According to the tests results, subsurface damage diagram models based on nanoindentation and nanogrinding are established, both of which exhibit the above evolution patterns as the indentation depth and grit depth of cut increases. However, there are some differences. In the nanogrinding process, nanocrystals and amorphous layers were found near the ground surface, which are related to the high strain rate grinding conditions and the unique material properties of monocrystalline β-Ga₂O₃ with low stacking fault energy. The results in this work contribute to an enhanced understanding of the deformation characteristics of monocrystalline β-Ga₂O₃ at macro and micro scales, while offering valuable insights for achieving damage control in ultra-precision machining processes.

Paper Link：https://doi.org/10.1016/j.matchar.2023.113441