Effects of hot working procedure on surface relief characteristic in an Fe–Mn–Si–Cr shape memory alloy

Abstract

The paper reports the evolution of surface relief and shape memory behavior in an Fe-28Mn-6Si-5Cr (mass%) shape memory alloy (SMA) as a function of the applied hot working procedure. The objective of this paper is to discuss the relationship between surface relief characteristic, structural changes and the type of hot working processing. Particular aspects concerning the relief of martensite plates were reported after the alloy was subjected to two types of hot working procedures, namely hot rolling and hot forging at 1273 K. The observations were performed by means of optical (OM) and atomic force (AFM) microscopy, on bi-dimensional and three-dimensional micrographs, corroborated with statistical evaluations. Aiming to reveal the presence of solid phase transitions enabled by hot working, differential scanning calorimetry (DSC) measurements were performed between room temperature and 673 K.Keywords: shape memory alloy / surface relief / hot working / atomic force microscopy / differential scanning calorimetry / phase transition Schlüsselwörter: Formgedächtnislegierung / Oberflächengestalt / Warmbearbeitung / Rasterkraftmikroskopie / Differentielle Scanning-Kalorimetrie / Phasenübergang