Development of Instrumented Indentation Microscope and Its Application to Indentation Contact Mechanics
Norio HAKIRI, Mototsugu SAKAI, and Tatsuya MIYAJIMA
Abstract:An instrumented indentation microscope is developed for determining the in-situ contact area during indentation loading/unloading, and then applied to examining the Meyer hardness and the elastic modulus of several engineering materials ranging from ductile metals to brittle ceramics. Since it is capable of making the in-situ optical observation of indentation contact impression and the determination of contact area that is synchronized to the hysteresis curve of indentation load-penetration depth relation, the mechanical properties determined on the indentation microscope are precise and reliable without any undesirable approximations and assumptions required for estimating the contact area in the conventional test systems. It is also demonstrated that the instrumented indentation microscope is very efficient for determining in a quantitative manner the in-situ contact profiles of impression (sink-in/pile-up profiles). Through the present studies for the experimental determinations of the Meyer hardness HM, elastic modulus E', and the consideration on the sink-in/pile-up profiles of contact impressions, it is emphasized that the direct measurement of contact area, Ac by the use of the indentation microscope is very essential in examining the mechanical properties of materials in micro-scales. The present work suggests that the instrumented indentation microscope will be a powerful tool in the science and engineering of indentation contact mechanics. Key Words:Indentation contact mechanics, In-situ measurement of contact area, Sink-in/pile-up, Elasticity/Plasticity