Mechanochemical reactions of the GaN-Al2O3 interface offer a novel principle for scientific and technological merits in the micro-/nano-scale ultra-precision surface machining.In this work,the mechanochemical reactions on Ga-and N-faced GaN surfaces rubbed by the Al2O3 nanoasperity as a function of the environmental humidity were investigated.Experimental results indicate that the N-face exhibits much stronger mechanochemical removal over the relative humidity range of 20％-80％than the Ga-face.Increasing water molecules in environmental conditions significantly promotes the interfacial mechanochemical reactions and hence accelerates the atomic attrition on N-face.The hypothesized mechanism of the selective water-involved mechanochemical removal is associated with the dangling bond configuration,which affects the mechanically-stimulated chemical reactions via altering the activation energy barrier to form the bonding bridge across the sliding interface.These findings can enrich the understanding of the underlying mechanism of mechanochemical reactions at GaN-Al2O3 interface and a broad cognition for regulating the mechanochemical reactions widely existing in scientific and engineering applications.

Jian GUO;Jian GAO;Chen XIAO;Lei CHEN;Linmao QIAN

School of Mechanical Engineering,University of South China,Hengyang 421001,China;Tribology Research Institute,State Key Laboratory of Traction Power Southwest Jiaotong University,Chengdu 610031,China;Advanced Research Center for Nanolithography(ARCNL),Science Park 106,Amsterdam 1098XG the Netherlands;Technology and Equipment of Rail Transit Operation and Maintenance Key Laboratory of Sichuan Province,Southwest Jiao tong University,Chengdu 610031,China

摩擦（英文）

[1]Jian GUO;Jian GAO;Chen XIAO;Lei CHEN;Linmao QIAN-.Mechanochemical reactions of GaN-Al2O3 interface at the nanoasperity contact:Roles of crystallographic polarity and ambient humidity)[J].摩擦（英文）,2022(07):1005-1018

Mechanochemical,nanoasperity,rubbed

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