Journal Article

Load-Dependent Nanoscale Material Removal Behaviors of β-Gasub.2Osub.3 Surface in Single-Point Diamond Scratching: From Plastic Plowing to Brittle Fracture

Wen, Chenhao, Guo, Jian, Lu, Yanqiang, Wu, Jiaqi, Fu, Haowei

2026

Overview

This study investigates nanoscale material removal behavior and its correlation with subsurface damage of (100)-oriented β-Ga[sub.2]O[sub.3] subjected to single-point diamond scratching across a range of normal loads. Using multi-scale characterizations, we elucidate the load-dependent transition from elastic deformation to plasticity-dominated removal and, ultimately, to brittle fracture. Under low-load conditions, β-Ga[sub.2]O[sub.3] exhibits a fully plasticity-dominated removal mechanism, characterized by smooth groove formation with surface pile-up and a crack-free subsurface containing only dislocations and stacking faults, suggesting that ductile-regime processing is achievable under appropriate mechanical conditions. As the normal load increases, the material enters a ductile–brittle transition regime, where plastic flow coexists with the initiation of micro shear cracks, accompanied by unstable fluctuations in the friction coefficient. Under high-load conditions, extensive brittle fracture becomes dominant, characterized by severe subsurface mixed cracking and large-scale material spalling. This research contributes to a deeper understanding of the machinability of β-Ga[sub.2]O[sub.3] materials with high hardness and brittleness in ultraprecision surface processing.

• Publisher: MDPI AG
• Subject: Semiconductors