Material removal and deformation mechanism in multiple nanoscratches of single crystal MgAl2O4
Zhao Jun, Yeshen Lan, Marian Wiercigroch, Wuqian Li, Shiwei Chen, Oltmann Riemer, Bernhard Karpuschewski
Abstract
• Material removal and deformation mechanism of single crystal MgAl 2 O 4 are first researched in multiple nanoscratches; • A multiple nanoscratches sequential classification is proposed; • Multiple nanoscratches penetration depth models are based on normal force; • Subsurface deformation mechanism in ductile removal regime is analyzed and observed; Single crystal MgAl 2 O 4 requires ultra-precision machining to achieve dimensional accuracy and surface quality due to its high hardness and brittleness. To investigate the effect of multi-abrasive scratch sequences on the material removal and deformation mechanism of single crystal MgAl 2 O 4 in ultra-precision machining. Multiple nanoscratches experiments with different sequences were conducted to demonstrate the randomness of the scratch sequence occurrence at the abrasive tip in ultra-precision machining. The interactions between multiple nanoscratches with different sequences were analyzed for their effects on the material deformation characteristics and surface morphologies of single crystal MgAl 2 O 4 . Additionally, theoretical models for the penetration depth of multiple nanoscratches with different sequences were established. The results show that multiple nanoscratches with different sequences affect the material removal and deformation mechanism of single crystal MgAl 2 O 4 , and the predictions of the penetration depth theoretical model align closely with the experimental results. TEM analysis results show that the subsurface deformation mechanism in the ductile removal region during multiple nanoscratches is primarily characterized by the transformation of single crystals into poly-crystalline of nanocrystalline.