Specimens Preparation Influence on Results of Micro-Tensile Tests

Abstract

Small sized specimens become more and more used nowadays and thus more attention is paid to small sized specimens techniques development. Small sized techniques are used for mechanical properties determination in cases when limited amount of the experimental material iv available, such as, evaluation of residual operation time of in service components, mechanical properties assessment of newly developed materials (e.g. severe plastic deformation techniques) and determination of local properties of larger components. Downsizing specimens dimensions lead to increasing demand on the quality of applied testing procedures and samples preparation. The current paper deals with Micro-Tensile Tests and specifically with parameters of specimens preparation on the test results. several preparation procedures are going to be compared with results obtained on the standard sized specimens. Moreover, also the grain size influence on results on small sized specimens is assessed here.

Novel Methods for High-Cycle Fatigue Life Determination

“…In the case of HCF specimens after turning, grinding was applied to reach the average roughness of 0.2µm by means of wet sanding with 320, 600 and 1200 grit silicon carbide sandpapers. Micro-tensile test with DIC (Digital Image Correlation) measurement were performed according to procedure described in [1][2][3][4] and the results was in the good agreement with standard tensile test, see Table 2. Subsequently, HCF tests on miniature specimens were conducted on the resonant fatigue testing machine Vibrophore Rumul using loads up to 20 kN in the tension-compression mode and on the servo-hydraulic testing machine MTS Bionix with a load capacity of 25 kN.…”

Damage tolerant design of additively manufactured metallic components subjected to cyclic loading: State of the art and challenges

“…The miniature specimens have been machined from AM bars by turning and electro discharge machining (EDM). The specimen surfaces are treated by a combined procedure of grinding and polishing in order to remove a thin surface layer affected by thermal erosion and a recast layer with micro-cracks at the machined surface [378]. Preliminary LCF and HCF investigations showed that the miniature specimens could be used for testing at room temperature as well as at elevated temperatures [75].…”