Effect of heat treatment on microstructures and mechanical properties of high vacuum die casting Mg–8Gd–3Y–0.4Zr magnesium alloy

2014 ◽  
Vol 24 (12) ◽  
pp. 3762-3768 ◽  
Author(s):  
Zhi-qin WANG ◽  
Bin ZHANG ◽  
De-jiang LI ◽  
Robert FRITZSCH ◽  
Xiao-qin ZENG ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Magnesium Alloy ◽  
Die Casting ◽  
High Vacuum ◽  
Vacuum Die Casting ◽  
Microstructures And Mechanical Properties

Study on Microstructures and Mechanical Properties of Die Casting Mg-xGd-3Y-0.5Zr Alloys

2013 ◽  
Vol 690-693 ◽  
pp. 44-48
Author(s):  
Feng Wang ◽  
Zhi Wang ◽  
Zheng Liu ◽  
Ping Li Mao
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Solution Heat Treatment ◽  
Die Casting ◽  
Solution Treatment ◽  
Small Variation ◽  
Strength Increase ◽  
Microstructures And Mechanical Properties ◽  
Zr Alloys

In this paper, developed a non-aluminum die casting magnesium alloys were studied based on Mg-xGd-Y-Zr（x=6, 8, 12 wt.%）alloys in cold chamber press. The microstructures and mechanical properties of die casting GWK alloys have been investigated using OM, SEM, XRD, EDS and mechanical property test. The experimental results show that with increasing Gd content of Mg-xGd-Y-Zr alloys, the tensile strength increase, but elongation decrease. In particular, die casting GWK alloys after short-term and low-temperature solid solution treatment (T4) have a small variation in grain size and more uniform microstructures, and the second phases distribute at the grain boundaries in form of discontinuous rod shape or granule shape, which result in an obvious improvement in tensile mechanical properties of alloys. The Mg-12Gd-3Y-0.5Zr die casting alloy exhibit maximum tensile strength after solution heat treatment, and the value is 269MPa at room temperature. The effect of solution heat treatment on die casting Mg-xGd-Y-Zr alloys was also discussed.

Optimization of Heat Treatment Process on Vacuum Die-Casting AT72 Magnesium Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 307-312
Author(s):  
Da Quan Li ◽  
Yong Liu ◽  
Jun Xu ◽  
Shuang Shao ◽  
Chun Shui Xu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Magnesium Alloy ◽  
Grain Boundary ◽  
Treatment Process ◽  
Die Casting ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Heat Treatment Process ◽  
Vacuum Die Casting ◽  
The Matrix

The effect of heat treatment on vacuum die-casting (VDC) AT72 magnesium alloy was studied. The optimal process of heat treatment was obtained. The result shows that the alloy was composed of α-Mg, Mg17Al12and Mg2Sn. After solution treatment at 686K for 24h, Mg17Al12completely dissolved in α-Mg matrix. With the aging treatment following solution treatment, Mg17Al12kept precipitating in the matrix and along grain boundary. Moreover, Mg2Sn distributed along the grain boundary did not disappear after solution treatment at 686K. This indicates that Mg2Sn phase exhibits very high thermal stability. The heat treatment process was optimized with solution at 686K for 24h plus ageing at 473K for 18h, in the condition of which AT72 magnesium alloy exhibits a maximum hardness with value of 90.8Hv. The successful application of heat treatment for AT72 magnesium alloy could be attributed to the elimination of the air bubble in the casing through VDC. However, the porosity in the cast couldnt be efficiently eliminated by VDC, which result in the growth of shrinkage pore.

scholarly journals Effect of Injected Oxygen Amount on the Gas Porosity and Mechanical Properties of a Pore-Free Die-Cast Al–Si–Cu Alloy

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1805
Author(s):  
Ho-Jung Kang ◽  
Ho-Sung Jang ◽  
Seong-Hyo Oh ◽  
Pil-Hwan Yoon ◽  
Gyu-Heun Lee ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Die Casting ◽  
High Vacuum ◽  
Distribution Analysis ◽  
T6 Heat Treatment ◽  
Gas Porosity ◽  
Before And After ◽  
Die Castings

With the rise in the demand for eco-friendly and electric vehicles, welding and heat treatment are becoming very important to meet the necessary weight reduction, complexity, and high functionality of die castings. Pore-free (PF) die casting is an effective process that enables heat treatment and welding due to low gas porosities. Indeed, this process affords castings of low gas porosity, similar to those attained by high-vacuum die casting. In this study, we compared the gas porosities of different castings fabricated by PF die casting using varied injected oxygen amounts. The castings were all subjected to T6 heat treatment and analyzed by computed tomography (CT) to compare their microstructure and mechanical properties before and after T6 heat treatment. The results revealed that with the increasing injected oxygen amount, the gas porosity of the specimens decreased while their mechanical properties increased. In particular, the gas porosity was the lowest at 1.26 L. Moreover, the 1.26 L specimen displayed the best tensile strength, yield strength, and elongation results. Finally, Weibull distribution analysis revealed that the tensile strength and elongation repeatability and reproducibility increased with increasing injected oxygen amount.

Effect of Heat Treatment on Microstructure and Mechanical Properties of Semi-Solid Formed Magnesium Alloy AZ91D

2010 ◽  
Vol 148-149 ◽  
pp. 346-352
Author(s):  
Dong Nan Li ◽  
Wen Zhe Chen ◽  
Jun Tian
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
Die Casting ◽  
Primary Phase ◽  
T6 Heat Treatment ◽  
Microstructure And Mechanical Properties ◽  
Alloy Az91d ◽  
Semi Solid

The semi-solid slurry of AZ91D magnesium alloy was prepared by twin-screw stirring mixer, the microstructure and mechanical properties of semi-solid formed magnesium alloy AZ91D produced by rheo-diecasting and conventional liquid die casting were investigated, respectively. The strengthen mechanism of the semi-solid formed magnesium alloy after heat treatment was analysed by EDS. The results show that the mechanical properties of semi-solid formed magnesium alloy can be enhanced markedly by T4 and T6 heat treatment, owing to decrease of the porosity and less segregation in casting, brittle eutectic compounds dissolves gradually into α-Mg matrix, and the primary phase α-Mg decomposes in the course of heat treatment. In as-cast state, the tensile strength, elongation and hardness of semi-solid formed magnesium alloy AZ91D are 222MPa, 2.3% and 74 HBS, respectively. In T4 heat treatment state, the tensile strength and elongation are increased by 13% and 210%, and in T6 heat treatment state, the tensile strength and hardness are increased by 11% and 16%. The mechanical properties of castings formed by conventional liquid die casting are deteriorated distinctly after T6 heat treatment due to its porosity and crack defects.

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