INDENTATION MEASUREMENTS USING A DYNAMIC-MECHANICAL ANALYZER

A dynamic mechanical analyzer equipped with a diamond indenter tip was used to measure the elastic modulus of polymeric coatings as well as various bulk materials. A fabricated indenter probe was used to indent bulk samples of aluminum and fused quartz, as well as gelatin and pol ystyrene films in order to compare the micron-level indentation measur ements with sub-micron (nanoindentation) techniques. The measured modu li were in agreement for ductile materials and thick films (> 20 mu m) , but limited displacement resolution, material cracking, and hydrosta tic pressure effects led to diverging values for thinner coatings and more brittle materials.