Impact of annealing on martensitic transformation of Mn50Ni42.5Sn7.5 shape memory alloy

Abstract

The impact of annealing on the structural and martensitic transformation of Mn50Ni42.5Sn7.5 (at.%) shape memory alloy was systematically investigated using a scanning electron microscope (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). According to XRD studies, martensite phase a 14M modulated monoclinic structure was detected, at room temperature, for as-cast and annealed alloys. In addition, it has observed that during annealing, the transition temperatures have increased relative to the cast alloy. Also, a high dependence between the cooling rate and activation energy has detected. The more detailed characterization of martensitic transition and account of thermodynamic parameters were examined after annealing. Response to Reviewers:Dear Sir, At first, I would like to thank the reviewer 1 for the constructive remarks and the interest discussions offer for our paper. The given questions pushed us to make another bibliography and discovered the interesting result deduced from the effect of annealing condition on martensitic transformation in a Mn-Ni-Sn alloy. We have considered all your suggestions, which are corrected in the manuscript as following:Responses for Reviewer 1 Comments Question 1: "English text is generally well written using straightforward expressions. However, there is occasional carelessness noticeable in the manuscript and they are better to be corrected by proof reading of the native English speaker." Response Thank you for your comment. The English language has been improved. Question 2: "Page 3, line 4; As you know, vapor pressure of Mn is very high and arc remelting of pure Mn might be very difficult. What was your plan for recycling Mn and control the composition? Meanwhile, evaporation of Mn and its deposition on the visor of the furnace could be another problem. Please explain in detail how did you perform Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation the melting process?" Response Yes, you are right, we detailed the melting process. The equipment used in this study is the Compact Arc Melter MAM-1 model of the commercial house Edmund Bühler. The precursors used to obtain the Mn50Ni42.5Sn7.5 (at. %) bulk alloy are: a Ni metal filament (purity> 99.98%), metallic manganese sheets (purity> 99.98%) and pieces of metallic Sn in the form of small spheres (purity> 99.99%). An extra 5 wt.% Mn was added to compensate for evaporation losses. Polycrystalline of about 4g were prepared by the melting of the precursors under argon atmosphere in a water-cooled copper crucible. The bulk alloy was melted four times, to ensure the homogeneity of the chemical composition. In our case, the starting elements have a high melting point, such as: Melting point of Ni= 1455C, Mn= 1246C, Sn= 231C. To better ensure the recycling of the Mn and control the composition, the elements were placed increasingly according to their melting temperatures more precisely the Sn and the Mn finally the highest Ni. The bulk alloy was fixed in a quartz tube filled wi...

Microstructure and Kinetics of Thermal Behavior of Martensitic Transformation in (Mn,Ni)Sn Heusler Alloy

“…It is clear that M s and M f both diminish as the cooling rate rises, but M s exhibits a considerably larger reliance that may also result from the DSC sample's slow thermal conduction. Similar results were reported most recently by Zheng et al and Bachaga et al [33,34]…”

“…It is clear that Ms and Mf both diminish as the cooling rate rises, but Ms exhibits a considerably larger reliance that may also result from the DSC sample's slow thermal conduction. Similar results were reported most recently by Zheng et al and Bachaga et al [33,34]. Based on the current result that the austenite phase's crystal structure is cubic L21, it is crucial to investigate the transformation's kinetics, specifically the activation energy, in order to gain a thorough understanding of the theoretical basis of MT.…”

Structure, Microstructure and Magnetocaloric/Thermomagnetic Properties at the Early Sintering of MnFe(P,Si,B) Compounds

“…Setting aside the case of micro-or nanostructured materials which involve specific mechanisms [30][31][32] and going beyond the simple aspect of sample purity or secondary phase content, the sample synthesis technique may exert an extrinsic control on the phase transition and therefore significantly affect the magnetocaloric performances. One of the most typical examples is the great sensitivity of martensitic transitions to microstructural details [33][34][35][36][37][38].…”