Casting in the Semi-Solid State of ZK60 Magnesium Alloy Modified with Rare Earth Addition

2014 ◽  
Vol 922 ◽  
pp. 694-699 ◽  
Author(s):  
E.P. Silva ◽  
Larissa Fernandes Batista ◽  
Bruna Callegari ◽  
Ivan Feierabend ◽  
Ricardo Henrique Buzolin ◽  
...  

In this work, the casting process under mechanical agitation in the semi-solid state was investigated for the production of ZK60 magnesium alloy modified with the addition of 2.5% wt ofmischmetal. The results show that this process enables the production of ingots with homogeneous chemical composition and free of shrinkage, inner defects and internal oxidation. The as-cast microstructure consists of an α-Mg matrix with globular grains reinforced by a grid of distinct intermetallics of Mg-Zn, Mg-Zn-RE and Mg-RE type along the grain boundaries. The yield strength at room temperature undergoes more than 50% increase during direct T5 aging, thus reaching 170 MPa. At 300°C, however, the dispersion of nanometric precipitates does not modify the hot deformation behavior of the aged alloy, which undergoes dynamic recrystallization in a similar manner to the as-cast alloy. DRX at 300°C is fastest for the alloy solution-treated at 500°C.

2009 ◽  
Vol 506 (1-2) ◽  
pp. 8-15 ◽  
Author(s):  
Zude Zhao ◽  
Qiang Chen ◽  
Yanbin Wang ◽  
Dayu Shu

2011 ◽  
Vol 335-336 ◽  
pp. 783-786
Author(s):  
Fu Yin Han ◽  
Lin Hai Tian ◽  
Hong Xia Wang ◽  
Wei Liang ◽  
Wen Xian Wang

Sr added ignition-proof AZ91D-0.3Be magnesium alloy was prepared. The influence of Sr content on microstructure and mechanical properties of the alloy was studied. Results show that the microstructure of ignition-proof AZ91D-0.3Be magnesium alloy is refined by a small amount of Sr addition. It is due to that the enrichment of a few Sr atoms in solid liquid interface in the process of magnesium alloy solidification inhibits grain growth and accelerates more nucleation. However, with increasing of Sr addition the microstructure is coarsened. By 0.01% Sr addition the tensile strength of as-cast experimental alloy is increased by about 25% and that of both the solid-solution and aged alloy is increased by about 40%. The elongation of as-cast alloy is increased by about 20% and that of solid-solution alloy increased by about 30%.


2006 ◽  
Vol 324-325 ◽  
pp. 499-502
Author(s):  
Ze Sheng Ji ◽  
Mao Liang Hu ◽  
Xiao Yu Chen

AZ91D magnesium alloy is prepared by hot extrusion of recycled machined chips and its fractures and mechanical properties are investigated at various extrusion conditions. Cold-press is employed to prepare extrusion billets of AZ91D magnesium alloy chips, and then the billets are hot extruded at 573K-723K with an extrusion ratio of 11:1. The results show that tensile strength and elongation of the extrusion magnesium alloy with the extrusion temperature of 673K and the extrusion rate of 0.08mm/s can reach 380MPa and 6%, respectively. Fracture surface presents a mix mechanism of dimple-like fracture and gliding fracture. Due to grain refinement by cold-press and hot extrusion, mechanical properties of extruded rods are much higher than those of as-cast AZ91D magnesium alloy. Also, much lower energy consumption is necessary for this recycling compared to the conventional casting process. Solid state recycling is an efficient method for magnesium alloy chips recycling.


2021 ◽  
Author(s):  
mohsen ostadshabani ◽  
Amir Baghani ◽  
Mohammad Reza Rahimipour ◽  
Mansour Razavi ◽  
Mohammad Zakeri ◽  
...  

Abstract Applying aluminum composite in the defense, aerospace and automotive industries depends on how they behave during the elasto-plastic form change. In addition to the factors responsible for changing the form of the alloy, many other factors have an impact on the behavior of the composite form change. In this study, the effect of casting type on the mechanical properties of Al-Si nano composites has been investigated. Due to the proper distribution of reinforcing particles, tensile strength in compo casting sample in semi-solid state is higher than sand casting and squeeze casting. In all samples, the tensile strength of the heat-treated samples has increased by about 30%. Tensile strength in compo casting sample in semi-solid state was obtained with higher nano particle reinforcing particles, which can be explained by the fact that the percentage of elongation in micro samples was lower than that of nano composite samples.


2005 ◽  
Vol 488-489 ◽  
pp. 397-400
Author(s):  
Hwa Chul Jung ◽  
Ye Sik Kim ◽  
Kwang Seon Shin

The demand for magnesium alloys has increased significantly during the past decade in the automotive and electronic industries where weight reduction becomes increasingly an important issue. At present, high-pressure die casting (HPDC) is a dominant process in production of magnesium alloy components. However, magnesium alloy components produced by HPDC suffer from porosity problem and this limits the enhancement of mechanical properties through subsequent heat treatments. The semi-solid processing (SSP) is an emerging new technology for near-net shape production of engineering components, in which the alloys are processed in the temperature range where the liquid and solid phases coexist. The SSP has various advantages over the conventional casting processes. It offers the castings with high integrity and less porosity and allows subsequent heat treatments for enhancement of mechanical properties. For these advantages, the SSP of magnesium alloys has received increasing attention in recent years. In the present study, the continuous casting process was developed for the production of magnesium billets for the subsequent SSP. The process utilizes an electromagnetic stirring system in order to obtain desired microstructure with an excellent degree of homogeneity in both microstructure and composition. Prototypes of an air conditioner cover and a telescope housing were produced using the SSP of the continuously cast magnesium alloy billets.


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