Zhengwen Yu

Microstructure and mechanical properties of asextruded Mg–xAl–5Sn–0·3Mn alloys (x = 1, 3, 6 and 9)

Abstract Properties of Mg–xAl–5Sn–0·3Mn alloys (x = 1, 3, 6 and 9) prepared by hot extrusion are reported. The orientation relationship between Mg2Sn precipitate and Mg matrix in Mg–9Al–5Sn–0·3Mn alloy was determined. The yield strength of the as extruded alloys initially decreased with increasing Al content, then increased for Al contents >6 wt-%. These changes are interpreted in terms of the effect of texture, grain size and second phase on the yield strength of the alloys.

Effect of microalloying with titanium on microstructure and mechanical properties of AZ91 magnesium alloy

Abstract In the present investigation, the influence of minor Ti addition on the microstructure and mechanical properties of as cast AZ91 magnesium alloy was investigated. The results indicated that the microstructure of the AZ91 alloy with 0·4 wt-% Ti was mainly composed of α-Mg matrix and β-Mg17Al12 eutectic phases. After the addition of 0·4 wt-% Ti to the AZ91 alloy, the average grain size was obviously decreased and the microstructure was drastically refined. The morphology of the β-Mg17Al12 phases was mainly changed from the original partially divorced eutectics to the fully divorced eutectics. A significant enhancement of the tensile properties was found because of titanium addition.

Effect of aluminium on the microstructure and mechanical properties of as-cast magnesium–manganese alloys

ABSTRACT In this paper, the effect of aluminium on microstructure and mechanical properties of as-cast magnesium–manganese alloy has been investigated by means of X-ray diffraction, optical microscopy and scanning electron microscopy. The results reveal that various Al–Mn intermetallic compounds form with an increase of Al content. As a result, microstructure of AM11 alloy has been effectively refined due to the formation of Al8Mn5 phase along the grain boundary, while Al addition is explained as the main reason on refining the microstructure of AM91 alloy due to its higher grain growth restriction factor value of ∼4.32. The tensile yield strength (TYS) has been improved steadily from 27.4 to 122.9 MPa with increasing Al content, because of the combined effects of grain boundary strengthening, solid solution strengthening and precipitation hardening behaviours.