Investigation of factors influencing microscopic interactions between the diamond indenter and material surfaces in nano-indentation

• Published in: Applied surface science Vol. 355; pp. 761 - 765
• Main Authors: Wei, Qilong, Li, Xiaoyuan, Yang, Qiang, Gao, Wei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.11.2015
• Subjects: Adhesion; Adhesion force; Austenitic stainless steels; Contact force; Diamond pyramid hardness; Elastic recovery; Fused silica; Indenters; Low carbon steels; Nano-indentation; Nanostructure; Steels; Unloading rate; Adhesion force; Unloading rate; Contact force; Nano-indentation; Elastic recovery
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2015.07.137

There had a critical Fmax to measure adhesion force between the diamond indenter and the FS, and it was about 20mN. And variation of measured adhesion force with Fmax could be fitted linearly when the latter was higher than its critical value, with slope −1.8615μN/mN. •Nano-indentation was adopted to study microscopic interactions in polishing process.•Measured contact force changed little when Fmax was less than its critical value.•Intrinsic mechanisms of variations of contact force was due to elastic recovery. Nano-indentation method was brought forward to replace atomic force microscopy (AFM) in simulating microscopic interactions between abrasive particles and material surfaces during polishing process. And main influencing factors including measuring parameters and material's properties were investigated thoroughly. It was found that contact force between the diamond indenter and a fused silica was about 200μN, while it was about 470μN between the indenter and an austenitic steel, and in both cases it did not vary with the maximal indentation force (Fmax) and the corresponding loading rate. While adhesion force between the indenter and surfaces of the two materials did not change with Fmax when the latter was less than its critical value, while it decreased monotonously with increased Fmax when the latter was higher than its critical value, with slope −1.8615 for the fused silica and −1.5403 for the austenitic steel, and the critical Fmax was about 20mN for the fused silica and about 50mN for the austenitic steel. According to analysis on elastic and plastic deformation during loading process and elastic recovery during unloading process, it was deduced that there would produce marked elastic recovery force when the unloading rate determined by Fmax was higher, which counteracted the measured adhesion force to some extent and made it less than its corresponding intrinsic value. And material's elasticity had an additional impact. Then it is better to adopt maximal indentation forces less than critical values of materials, to obtain accurate adhesion forces between the indenter and material surfaces, and to simulate accurately microscopic interactions during polishing process.