RESUMO Neste trabalho é apresentado uma revisão de um conjunto de sistemáticas para a estimativa de propriedades elasto-plásticas de materiais metálicos e cerâmicos pelo método de indentação instrumentada. As sistemáticas analisadas contemplam a metodologia de Oliver e Pharr original e com uma modificação da função de profundidade de contato de maneira a torná-la mais próxima das medições experimentais além de diferentes métodos analíticos baseados na energia de deformação (Stilwell e Tabor; Tuck Giannakopoulos e Suresh e Malzbender). Os resultados obtidos para o módulo de elasticidade e a dureza resultantes da aplicação das sistemáticas propostas foram comparados com os valores obtidos da literatura referentes ao aço inoxidável austenítico 316L, alumina e boreto de ferro e cromo. De modo geral os resultados encontrados para a dureza e módulo de elasticidade calculados utilizando as diferentes sistemáticas apresentaram boa coerência com os valores da literatura, entretanto algumas metodologias necessitaram de aplicações de fatores de correção para a caracterização correta das propriedades das amostras.

ABSTRACT This paper presents a review of a different number of systematics for the estimation of elastoplastic properties of metallic and ceramic materials by instrumented indentation testing. The analyzed methodologies include Oliver and Pharr's original methodology and a modification of the contact depth function in order to make it closer to experimental measurements besides different analytical methods based on strain energy (Stilwell e Tabor; Tuck Giannakopoulos and Suresh and Malzbender). The results obtained for the Young’s modulus and hardness resulting from the application of the proposed methodologies were compared with the values obtained in the literature for the austenitic stainless steel 316L, aluminum oxide and iron chromium boride. In general, the results obtained for the hardness and modulus of elasticity calculated using the different systematics presented good coherence with the values of the literature, however some methodologies required the application of correction factors for the correct characterization of the properties of the samples.

Depth sensing indentation study was conducted in a Fischerscope H100V machine, equipped with a Vickers indenter with a tip roundness of approximately 1330 nm. Tests were carried out on soda-lime glass, fused silica, sapphire, aluminum (1100 alloy), high alloyed steel, titanium and copper. The widely used iterative method of Oliver and Pharr was unsuccessful in the attempts to analyze machine compliance and indenter area function. Therefore, an alternative procedure was adopted. The alternative procedure is based on the ratio between maximum load and unload stiffness squared, Pm/Su². It was found that this procedure, which is not iterative, gives good results. A careful study of the Pm/Su² ratio, lead us to conclude that the Fischercope machine has a low compliance which depends on the sample mounting. This low compliance in conjunction with the recent discovery of the dependence of beta factor on the tip roundness/maximum depth ratio, which appears in the relation between contact stiffness and contact area, explains why the iterative method does not converge. However, variations in beta and machine compliance produces deviation on the hardness and elastic modulus lower that 6% with respect to expected values for the materials and the machine studied in this work.