The texture and anisotropy of magnesium–zinc–rare earth alloy sheets

Superior light metals by texture engineering: Optimized aluminum and magnesium alloys for automotive applications

The extrusion behaviour, texture and tensile ductility of five binary Mg-based alloys have been examined and compared to pure Mg. The five alloying additions examined were Al, Sn, Ca, La and Gd. When these alloys are compared at equivalent grain size, the La- and Gd-containing alloys show the best ductilities. This has been attributed to a weaker extrusion texture. These two alloying additions, La and Gd, were found to also produce a new texture peak with 〈 1 1 2 ¯ 1 〉 parallel to the extrusion direction. This “rare earth texture” component was found to be suppressed at high extrusion temperatures. It is proposed that the 〈 1 1 2 ¯ 1 〉 texture component arises from oriented nucleation at shear bands.

The origin of “rare earth” texture development in extruded Mg-based alloys and its effect on tensile ductility

On the role of non-basal deformation mechanisms for the ductility of Mg and Mg–Y alloys

Particle effects on recrystallization in magnesium―manganese alloys: Particle―stimulated nucleation

The sheet formability of current magnesium alloys at ambient temperatures is poor; however, the formability at moderately elevated temperatures can be excellent. Cylindrical cup drawing tests are used to compare the warm forming characteristics of conventional alloy AZ31B with alloys containing lithium oryttrium solid solutions. While both types of experimental alloy can have better room-temperature ductility (ef∼25–30%) than AZ31B, only the lithium alloy has comparable or better deep-drawing capacity. The results are discussed in terms of the sheet anisotropy. Particular attention is drawn to the fact that magnesium alloys exhibit poor bending ductility due to their anisotropy and mechanical twinning-induced tension-compression strength asymmetry.

Mg sheet metal forming: Lessons learned from deep drawing Li and Y solid-solution alloys

Effect of Friction Material on the Relative Contribution of Thin-Film Friction to Overall Friction in Clutches

Effective axle oils must efficiently transfer torque from the drive-train to the wheels, while maintaining low axle oil operating temperatures. Previous studies have shown that fluids, which form thicker elastohydrodynamic (EHD) films and have lower EHD friction, have higher torque transfer efficiencies (TE) and lower axle oil operating temperatures (OT). In general, oils with higher viscosities form thicker films and those with lower viscosities have lower EHD friction. Therefore, optimizing oil's rheological properties to maximize TE and minimize OT is difficult. In this paper, we examine two approaches to maintaining high TE while reducing OT. One approach is to minimize boundary friction since previous studies have shown that the boundary frictional properties of oils influence OT and not TE. A second approach is to more thoroughly examine the effect of rheology on film thickness and EHD friction. Film thickness and EHD friction are related to the high temperature high shear viscosity and pressure-viscosity coefficient of oils. We have found that oils with high pressureviscosity coefficients and low high temperature high shear viscosities will form thick films and have low EHD friction. This optimized combination of physical parameters, along with lowering the boundary friction coefficient of axle oils, results in oils with high TE and low OT. Copyright © 2006 John Wiley & Sons, Ltd.

Jeremy Senn

Papers

The texture and anisotropy of magnesium–zinc–rare earth alloy sheets

Mg sheet metal forming: Lessons learned from deep drawing Li and Y solid-solution alloys

Effect of Friction Material on the Relative Contribution of Thin-Film Friction to Overall Friction in Clutches

Reduction in axle oil operating temperatures by fluids with optimized torque transfer efficiencies

Improved Understanding of Axle Oil Rheology Effects on Torque Transfer Efficiency and Axle Oil Operating Temperature