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Advantages of Cu based shape memory alloy include amongst other features, high transformation temperature, low cost of production, ease in manufacturing processes and ability to vary the achieved properties through alloying additions. It has been often reported that these alloys are very sensitive to the alloying additions in terms of properties achieved and phase precipitation necessary for development of shape memory properties. This behaviour in Cu based shape memory alloys i.e. being very sensitive to its constituents can be used positively to design alloys with pre set properties if the alloying additions and their percentages are properly controlled.In an attempt to understand the effect of different alloying additions, 2% of different elements [Zn, Si, Mg & Cr] were added to a known Cu-based shape memory alloy [Cu-12.5 wt% of Al-5 wt % of Mn]. The objective was to ascertain changes or improvements achieved due to the additions in terms of microstructural changes, hardness, phase precipitation and transformation temperatures. Attempts have been made to analyze the changes in properties achieved in the base Cu-Al-Mn alloys due to the quaternary additions. Grain structure with α+β phases, which is a pre requisite for martensite formation on quenching is seen in all the alloys indicating that all the alloys have potential to exhibit the shape memory behaviour. The martensite formation with different morphologies is observed in the quenched samples however. XRD results have identified the precipitated phases to be the martensitic phases. The DSC results indicate clear transformation peaks in most of the samples with significantly high transformation temperatures. The findings confirm the variation in properties achieved due to different additions and improvements achieved in terms of higher transformation temperatures and martensite formation due to the alloying additions. An attempt has been made to understand the findings.

The present research investigated the tribological and the thermal properties of Mg-3Al-xGNP alloy nanocomposites, fabricated through a powder metallurgy route with microwave assisted sintering followed by hot extrusion. Graphene nanoplatelets (GNPs) were incorporated as reinforcements in different amounts (0.1 wt.%, 0.3 wt.%, and 0.5 wt.%) into pure Mg and Mg-3Al alloy. The values of coefficient of friction and wear rate of pure Mg, Mg-3Al alloy, and Mg-3Al/xGNPs (x = 0.1 wt.%, 0.3 wt.%, and 0.5 wt.%) nanocomposites were evaluated on a pin-on-disc tribometer under dry sliding conditions, and scratch testing was performed under a vertical load of 9.8 N. The ignition temperatures of Mg-3Al-0.1GNP, Mg-3Al-0.3GNP, and Mg-3Al-0.5GNP were respectively increased by 2.31 %, 5.34 %, and 5.7 %. It was noticed that the reinforcement of 0.3 wt.% GNP yielded the best mechanical and tribological properties.