On the Indeterminacy in Hardness of Shape Memory Alloys

Abstract

Abstract: The present communication addresses an interesting problem related to the indeterminacy in hardness of superelastic NiTi reported by Xu et al. The origin of the indeterminacy is attributed to the inadequacy of the conventional Vickers hardness testing measurement which does not record elastic deformation, and thus the indeterminacy may be removed with suitable techniques. Concepts of hardness in relation to deformation are clarified. Recommendations for measuring the hardness of NiTi and other elastic-plastic materials are suggested, together with comments on the advantages and disadvantages of each of these methods.

Key words: Hardness, Elastic-plastic materials, Elastic recovery, Vickers microhardness test, NiTi, SMA

F.T.Cheng. On the Indeterminacy in Hardness of Shape Memory Alloys[J]. J Mater Sci Technol, 2004, 20(06): 700-702.

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