A discrete element method for mechanical behavior analysis of single-crystal silicon at different temperatures

Abstract

Single-crystal silicon (sc-Si) is a typical infrared material widely used in industries such as semiconductors and infrared imaging. At room temperature, sc-Si exhibits high hardness and brittleness, making it prone to defects like collapse and crack during processing. However, at elevated temperatures, sc-Si can undergo plastic deformation, which is of great significance for improving its manufacturing accuracy. Therefore, the effect of temperature on mechanical behavior of sc-Si was analyzed. Three-dimensional discrete element method (DEM) was used to simulate the effect of temperature on crack generation and propagation during the deformation of sc-Si. Then, nanoindentation and scratching tests were performed to compare the material's mechanical properties and removal processes at various temperatures. The results shows that the ductile machinability and the inhibition of crack propagation improve with increasing temperature. As the temperature rises, the hardness decreases, while the elastic modulus increases. The critical load required to induce cracks increases from 60 mN at room temperature to 100 mN at 400 °C. Elevated temperatures enhance the depth of the ductile-brittle transition of sc-Si, helping to suppress crack formation during scratching. These findings provide valuable insights into the deformation behavior of sc-Si, offering support for the manufacturing of sc-Si.