Papers by Keyword: AZ Magnesium Alloy

Abstract: In this research, AZ31 and AZ91 magnesium alloys were used as hydrogen storage materials to compare the effects of equal channel angular pressing (ECAP) and high energy ball milling (HEBM) processes on the hydrogen storage properties. In addition, the effects of using different AZ magnesium alloys (AZ31 and AZ91) with the same processes and parameters on the hydrogen storage properties were investigated. The results show that the crystal size of AZ magnesium alloy has been decreased by both ECAP and HEBM processes. It was also revealed that AZ31 magnesium alloy processed by ECAP route B_C with 8 passes has faster absorption and desorption rate than AZ31 magnesium alloy processed by HEBM ball material ratio 30:1 with 300rpm. The capacity of two samples is 7.0 and 6.8 wt.%. The AZ91 magnesium alloy processed by HEBM ball material ratio 30:1 with 300rpm has faster hydrogen absorption and desorption rate than that of AZ91 magnesium alloy processed by ECAP route B_C with 8 passes at 375^oc. The capacity of two samples is both 6.7 wt.%.

Abstract: Y and Gd are vital alloying elements to the AZ magnesium alloys. It is due to their functions mainly on solid solution strengthening and age strengthening. This paper reviews effect of Y, Gd on mechanical properties of AZ-series magnesium alloys. The future development direction is pointed.

Abstract: The electrochemical behavior of a new magnesium alloy (AZ61) containing rare earth elements-cerium (Mg-Al-Zn-Mn-Ce alloys) was investigated in 3% NaCl electrolyte using electrochemical methods such as linear sweep voltammetry, Tafel curves and electrochemical impedance spectroscopy. Scanning electron microscopy was used to characterize the surface morphologies of magnesium and its alloys. The results shows that compared with that of the most commonly used Mg alloy–AZ61, the cerium containing magnesium alloy exhibited higher electrochemical activity, and higher corrosion resistance. The electrochemical activity of Mg-Al-Zn-Mn-Ce was higher than that of Mg and Mg-Al-Zn-Mn-Ce alloys in 3% NaCl. The corrosion resistive order decreased in the following sequence: Mg-Al-Zn-Mn-Ce > Mg-Al-Zn-Mn > Mg. The electrolytes favored anodic magnesium oxidation, but the alloying element of Ce facilitated the formation of dense passive films on alloy surfaces.

Abstract: The powders of Al-Mn phases were obtained from the as-cast, as-rolled and as-extruded AZ magnesium alloys (AZ31, AZ61) by using the extraction technology, which was found to be one of the effective methods for analyzing Al-Mn phases in the AZ magnesium alloys. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersion X-ray detector (EDX) were used to investigate the structure and morphology of these compound powders. The results showed that manganese existed in both the way of Al8Mn5 phases and dissociated manganese particles in the AZ magnesium alloys, and rolling or extrusion process did not change the type of the Al8Mn5 phases. SEM observation showed that Al8Mn5 phases were formed mainly in dendrite and leaf shape with the size of 15-100μm in the as-cast AZ magnesium alloys, and were broken into fine spherical fragments with the size of about 4-5μm after rolling or extrusion.

Abstract: The effect of Al content on the microstructural characteristics, tensile and creep properties of Mg-xAl-Zn alloy was investigated. The molten Mg-(3~11)Al-Zn alloys of 700°C were poured into the permanent mould designed to prepare the specimens used in this study. Tensile and creep tests were carried out for each Mg-Al based alloys. Results show that creep resistance decreased while tensile strength improved with increasing Al contents. Microstructural study revealed that morphology and distribution of non equilibrium Mg17Al12 phase is main factor determining the tensile and creep properties of as cast Mg-xAl-Zn alloys. The final purpose of this study is to construct the database of already used Mg-Al based alloy and to develop the heat resistant magnesium alloys to apply transportation systems such as automobile.