(1. School of Civil Engineering，Shaoxing University，Shaoxing，Zhejiang 312000，China；2. Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province，Shaoxing，Zhejiang 312000，China；3. School of Mechanics and Civil Engineering，China University of Mining and Technology(Beijing)，Beijing 100083，China；4. Institute of Rock Mechanics，Ningbo University，Ningbo，Zhejiang 315211，China)
Abstract：The difference between the mechanical properties of rock mineral components is a key factor affecting the macroscopic friction behavior. Based on the target test method，the indentation mechanical properties of sandstone minerals are tested under eight normal loads，and the scratch friction properties of these minerals are studied under basically stable normal load. The results show that as the normal load increases，the deformation parameters(hardness and elastic modulus) of hard-phase minerals exhibit a negative indentation size effect，while the indentation size effect of deformation parameters of soft-phase minerals is not obvious，and the comprehensive basic stable normal load for the four minerals is determined as 8 mN. Under the stable normal load，as the scratch length increases，the friction force of quartz and albite in the hard-phase minerals increase rapidly and then remain stable，while the friction force of calcite and chlorite in the soft-phase minerals both increase rapidly and then slowly. Statistical calculations show that the average elastic recovery rates for the four minerals are 13.29%，15.81%，35.91% and 42.28% respectively. Further combined with the analysis of microscopic mechanism，it is found that dislocation creep and dislocation evolution of minerals are the key factors affecting the indentation size effect and scratch stick-slip behavior respectively. The above research results provide reference significance for the study of correlation between macro and micro mechanical behaviors of rocks.
