Papers by Keyword: Magnesium Die-Castings

Abstract: The wear properties of TFHS-1 hot work steel developed by Tsinghua University for magnesium die casting application was studied at elevated temperature with the help of GWY-2000 high temperature wear tester. The result showed that the oxidation wear is the main wear mechanism at high temperature with dry abrasion, which was also accompanied by some extent of adhesive wear and abrasive wear. Heat treatment conditions of TFHS-1 steel have an important effect on its anti-abrasion properties. In this paper, the higher temperature of tempering may result in the better wear resistance.

Abstract: A series of AM60B, die-cast magnesium alloy specimens have been examined using xray tomography at spatial resolutions from 1 – 20μm and further characterized in uniaxial tension. This paper first reports the utility of a critical strain model to link the local area fraction of porosity and the fracture strain. A discussion of the trade-off between predictive accuracy and the spatial resolution of the imaging technique is also presented in order to address the technological implications of these results. In the second half of the paper, serial tomographic imaging is used to illustrate the evolution of damage with increasing uniaxial strain. The implications are discussed with respect to numerical modeling of the performance of die-cast magnesium components.

Abstract: The normal and inverse solute macro-segregation are known to occur in Al and other nonferrous alloy castings and have been well studied and documented. However, these phenomena have not been investigated in the high-pressure die-cast Mg-alloys. Consequently, the effects of macro-segregation on the mechanical properties of cast Mg-alloys have not been characterized. The objective of this contribution is to investigate the effects of inverse macro-segregation and porosity on the fatigue behavior of high-pressure die-cast AM60 alloy. It is observed that the inverse macro-segregation of eutectic phase at the cast surfaces adversely affects the fatigue behavior: the fatigue resistance decreases substantially due to the presence of the surface segregation.