No abstract

No abstract

The method of using wear maps in assessing tool wear over a range of cutting conditions was presented by Lim et al. in 1993 for turning steel using high-speed steel (HSS) tools. Since then this approach has rarely been studied or critically reviewed. The use of reliable wear maps can aid in assessing the wear rate and wear mechanism of cutting tools over a feed rate to cutting velocity plane. The focus of this paper is on improving the integrity of such wear maps. Unified cutting tests were undertaken to explore the effect of two different grades of carbide tooling on wear performance within a range of recommended cutting conditions. The methodology for developing such maps, as well as the underlying assumptions, was critically reviewed in light of two new wear maps created for different carbide grades. Additionally, by utilising energy dispersive X-ray (EDX) analysis and wear patterns, the paper presents new evidence in support of mechanisms responsible for the safety zone. Understanding the wear mechanisms in the low tool wear zone is important for developing extended life tooling.

No abstract

High temperature ternary Ti50Ni25Pd25 and quaternary Ti50Ni20Pd25Cu5 shape memory alloys were developed in vacuum arc melting furnace using high purity constituent elements. Half numbers of samples were solution treated at 900 °C for 2 hrs and remaining were aged at 600 °C for 3 hrs. Both alloys were characterized for microstructure analysis and mechanical properties. After aging the alloys, no significant change in microstructure was observed in ternary alloy however, fine precipitates of bright color were found along the grain boundaries in quaternary alloy. The mechanical properties of ternary and quaternary alloys were found to be improved significantly. Microhardness of ternary alloy was increased by 18 Hv whereas for quaternary alloy the same property was improved by 24 Hv. Yield stress of ternary and quaternary was observed to be enhanced by 10 MPa and 9 MPa respectively. Similarly the fracture stress was observed to be increased by 9 MPa and 13.4 MPa. Conversely, the fracture strain of ternary and quaternary alloys was reduced by 0.5% and 0.35% respectively. From these results it can be established that aging at 600 °C is beneficial to improve the mechanical properties of both alloys however, quaternary alloy responded more actively as compared to ternary alloy.