Papers by Author: Anil K. Sachdev

Abstract: This paper summarizes the development of new cast and wrought magnesium alloys using computational thermodynamics tools and experimental approach. The Mg-Al-Ca alloys show excellent creep resistance due to the formation of high-temperature (Mg,Al)₂Ca phase. The Mg-Al-Sn alloys are designed for mechanical properties and corrosion resistance through the optimization of Mg₁₇Al₁₂ and Mg₂Sn phases in the microstructure. In the Mg-Zn-Ce system, Zn provides strength through solid solution strengthening while Ce increases the ductility via improved texture. Mg-Nd-Zn is a heat-treatable alloy system based on the precipitation hardening of Mg₁₂Nd phase.

Abstract: Although mass reduction can be associated with additional costs, a decision to lightweight a structural subsystem may, depending on when in the vehicle development process the decision is taken, result in secondary (additional) mass savings such that the value of lightweighting is substantially increased. This paper overviews a method to estimate the potential for secondary mass savings in different vehicle subsystems. We close by describing current research efforts aimed at developing new lightweight product solutions for both body and powertrain applications along with commensurate manufacturing processes.

Abstract: Uniaxial hot compression tests were performed at constant temperature (T) and strain rate (ε& ) in the ranges of 200-500 °C at an interval of 50 °C and 0.001-20 s-1. The flow stress data were used to develop the extrusion limit diagram for AZ31 and AM30 magnesium tubes. The extrusion limit diagram shows a wide region available for extruding AZ31 and AM30 seamless tubes, and comparison of the two extrusion limit diagrams shows that, the extrudability of AM30 alloy is better than that of AZ31 alloy. Actual extrusion trials validated the predicted temperature rise limit curve corresponding to the occurrence of surface cracking during the extrusion process. Magnesium tubes were successfully extruded according to the safe regions identified by the extrusion limit diagram.

Abstract: An appropriate temperature (150-200°C) bending process has been developed for AZ31 and AM30 magnesium alloy tubes, and the optimum bending process parameters were obtained using a Design of Experiments (DOE) method. The development of this process was one of the key factors for use of magnesium tubes in automotive components for vehicle weight reduction. The tensile properties and deformation microstructure of magnesium alloys at elevated temperatures indicated that temperature of 150-200°C which might be suitable for hydroforming and other forming processes.