Liu Zuyan

Finite element simulation of a new deformation type occurring in changing-channel extrusion

Abstract There has been a number of investigations in recent years reporting the results obtained on the structure and properties of metals deformed to large strain. Being deformed to large strain, ultra-fine grains (UFG) are usually formed, and materials with UFG structure display many abnormal characteristics, which have attracted a growing research interest. The method often used to obtain large strain is equal-cross-section lateral extrusion (ECSLE) or equal channel angular pressing (ECAP). However, according to the simulation results, there is large tensile stress in the workpiece during deformation, which may lead to cracking. In this paper, a new method, changing channel extrusion (CCE), is presented, which could decrease the tensile stress and increase the hydrostatic pressure in the workpiece, which is good for the plastic deformation of low ductility materials.

Finite-element analysis of the load of equal-cross-section lateral extrusion

Abstract The curves of load versus displacement during the equal-cross-section lateral extrusion process have been measured and also calculated using the finite-element method (FEM), the calculated results being in good accordance with the measured results. Furthermore, the effects of many influencing factors on load have been analyzed in detail using the FEM.

Hydrogen storage properties of the Mg–Ni–CrCl3 nanocomposite

The effects of the addition of the transition metal chloride CrCl3 on the hydriding and dehydriding behavior of Mg–3 wt.% Ni hydrogen storage material were investigated. The characteristics of the ball-milled nanocomposite Mg–3 wt.% Ni–1CrCl3 such as hydriding capacity in the ball-milling process and the kinetics of hydriding/dehydriding were examined. The hydrogen absorption capacity of the composite is greatly increased in the ball-milling process under hydrogen pressure (0.5 MPa). The absorption rate of the composite is fast and the hydrogen storage capacity is more than that of the sample without CrCl3.