scholarly journals Microstructure and Tensile Properties of the Mg-6Zn-4Al-xSn Die Cast Magnesium Alloy

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 113
Author(s):  
Jin Zhou ◽  
Hamid Jafari Nodooshan ◽  
Dejiang Li ◽  
Xiaoqin Zeng ◽  
Wenjiang Ding
Keyword(s):  
Tensile Properties ◽  
Hot Tearing ◽  
Age Hardening ◽  
Peak Hardness ◽  
Dendrite Structure ◽  
Die Cast ◽  
Cast Alloys ◽  
Peak Aged ◽  
Cast Magnesium ◽  
Hot Tearing Susceptibility

The effect of various Sn contents (1–2 wt. %) on the microstructure, age hardening response, and tensile and casting properties of the high-pressure die cast Mg-6Zn-4Al alloy were studied. All as-cast alloys consisted of α-Mg and icosahedral quasi-crystalline phase; and the addition of 2% Sn caused the formation of Mg2Sn phases. Dendrite structure and eutectic phases were observably refined by Sn addition. The hot tearing susceptibility of the die cast Mg-6Zn-4Al alloy prominently decreased with increasing Sn addition. During T6 heat treatment, Sn addition did not obviously affect the time to reach peak hardness, but significantly enhanced the age hardening response and improved the strength of alloys under peak-aged conditions. Compared to single aging, double aging resulted in the higher density of finer β1′ and β2′ precipitates. The double aged Mg-6Zn-4Al-1Sn alloy offered the optimum tensile properties among all conditions. The yield strength, ultimate tensile strength, and elongation were 209 MPa, 305 MPa, and 4.3%, respectively.

The Effect of Natural Pre-Ageing on the Mechanical Properties of Rheo-High Pressure Die Cast Aluminium Alloy 2139

2015 ◽  
Vol 828-829 ◽  
pp. 244-249 ◽  
Author(s):  
Levy Chauke ◽  
Pfarelo Daswa ◽  
Heinrich Möller ◽  
Gonasagren Govender
Keyword(s):  
High Pressure ◽  
Aluminium Alloy ◽  
Tensile Properties ◽  
Casting Process ◽  
Hot Tearing ◽  
Age Hardening ◽  
Peak Hardness ◽  
Artificial Ageing ◽  
Significant Difference ◽  
Precipitation Phenomena

Near-net shape casting of wrought aluminium alloys has proven to be difficult due to hot tearing. The Council for Scientific and Industrial Research (CSIR) has successfully processed wrought aluminium alloy 2139 into plate castings using the Rheo-high pressure die casting process (R-HPDC). Alloy 2139 is a Ag-containing aluminium alloy from the Al-Cu-Mg 2xxx series family. The addition of Ag enhances the age hardening response through the formation of co-clusters that act as precursors to the formation of plate-like Ω precipitates. These co-clusters typically form during natural ageing and 12-24 h of natural pre-ageing is normally specified before artificial ageing in Ag-containing Al-Cu-Mg alloys. The T6 hardness and tensile properties of R-HPDC 2139 alloy were investigated with and without natural pre-ageing. It is shown that there is no significant difference in both peak hardness and tensile properties in R-HPDC alloy 2139 with and without natural pre-ageing. The possible precipitation phenomena in both cases are discussed.

Effect of Silicon on the Microstructure, Tensile Properties and Hot Tearing Susceptibility of AZ91E Alloy

2012 ◽  
Vol 706-709 ◽  
pp. 3046-3051
Author(s):  
Comondore Ravindran ◽  
Sophie Lun Sin
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Tensile Properties ◽  
Room Temperature ◽  
Hot Tearing ◽  
Chinese Script ◽  
Az91 Alloy ◽  
Solidification Behavior ◽  
Last Stage ◽  
Hot Tearing Susceptibility

This Research Focused on Studying the Effect of Silicon on the Hot Tearing Susceptibility of Permanent Mould Cast AZ91E Magnesium Alloy. Varying Amounts of Silicon (0.5, 1.0 and 1.5 Wt.%) Were Added to AZ91E in the Form of an Al-53 Wt.% Si Master Alloy. the Microstructure, Grain Size and Solidification Behavior of each Alloy Were Characterized and Related to their Tensile Properties and Hot Tearing Susceptibility. the Results Showed that the Tensile Strength and the Elongation of AZ91 Alloy Decreased with the Addition of Silicon at Room Temperature, due to the Formation of Chinese Script Mg2si Particles. however, Silicon Significantly Reduced the Hot Tearing Susceptibility of AZ91E. this Was Attributed to the Reduction of the Grain Size and the Decreased Freezing Range of AZ91E, which Contributed to Improve the Interdendritic Feeding during the Last Stage of Solidification.

scholarly journals Residual Stresses of the As-Cast Mg-xCa Alloys with Hot Sprues by Neutron Diffraction

2014 ◽  
Vol 996 ◽  
pp. 592-597
Author(s):  
Jiang Feng Song ◽  
Yuan Ding Huang ◽  
Karl Ulrich Kainer ◽  
Wei Min Gan ◽  
Norbert Hort
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Hot Tearing ◽  
Cast Alloys ◽  
Hot Tearing Susceptibility

Residual stresses in Mg-xCa (0.5 wt. % and 1.0 wt. %) cast alloys were investigated by neutron diffraction using a mould with two preheating temperatures of 250 °C and 450 °C. Results show that the increase of Ca content decreases the residual stress in the hot sprue region. These results are quite in agreement with those obtained by the measurement of hot tearing susceptibility, which shows the increment in Ca content improves the castability of Mg-Ca alloys.

scholarly journals Age hardening heat treatment behavior of as-cast Mg–Zn–Al alloys

2021 ◽  
Vol 15 (57) ◽  
pp. 350-358
Author(s):  
Hiralal S. Patil ◽  
D. C. Patel
Keyword(s):  
Heat Treatment ◽  
Magnesium Alloys ◽  
Ternary Eutectic ◽  
Al Alloys ◽  
Age Hardening ◽  
Peak Hardness ◽  
Time Intervals ◽  
Cast Alloys ◽  
Dta Studies ◽  
Hardening Heat Treatment

Magnesium alloys have generated renewed interest as a light alloys; replacing some conventional structural materials for weight reduction in applications like aerospace, automotive and electronics industries. In interior components and powertrains, cast alloys are widely used and represent more than 99% of magnesium alloys used today, whereas only a few wrought products are used. Mostly in automotive applications, Mg-engine block can noticeably reduce the weight and consequently its fuel consumption and environmental impact. Due to solid-state precipitates, these alloys are strong in nature and are produced by an age-hardening heat treatment process. In the present work the age hardening behavior of the as cast Mg–Zn–Al alloys (ZA85 alloy) in the composition of 8 wt. %Zn, 5 wt. %Al has been investigated. Through the differential thermal analysis (DTA) studies, it has been found out that dissolution temperature of ternary eutectic precipitates is present in the alloy. Based on the DTA results, the as cast samples have been solutionised at 360 °C temperature for different intervals of time. Solutionising time has been optimized from the enthalpy values of un-dissolved precipitates. The solution treated samples have been then aged at temperature of 180° C for different time intervals. From the peak hardness values, the ageing conditions have been optimized.

An A Priori Hot-Tearing Indicator Applied to Die-Cast Magnesium-Rare Earth Alloys

2014 ◽  
Vol 45 (8) ◽  
pp. 3586-3595 ◽  
Author(s):  
Mark A. Easton ◽  
Mark A. Gibson ◽  
Suming Zhu ◽  
Trevor B. Abbott
Keyword(s):  
Rare Earth ◽  
A Priori ◽  
Hot Tearing ◽  
Rare Earth Alloys ◽  
Die Cast ◽  
Cast Magnesium ◽  
Hot Tearing Indicator

Effect of the Zn/Mg Ratio on Microstructure and Mechanical Properties in Al-Zn-Mg Alloys

2014 ◽  
Vol 794-796 ◽  
pp. 479-482 ◽  
Author(s):  
Masatomo Nishi ◽  
Kenji Matsuda ◽  
Naoya Miura ◽  
Katsumi Watanabe ◽  
Susumu Ikeno ◽  
...  
Keyword(s):  
High Strength ◽  
Hardness Measurement ◽  
Tensile Tests ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Age Hardening ◽  
Peak Hardness ◽  
Number Density ◽  
Peak Aged Condition ◽  
Peak Aged

It is well know that the 7000 series Al-Zn-Mg alloy has good age hardening ability and high strength among commercial aluminum alloys. In this study, hardness measurement, tensile test, SEM and TEM observation have been performed in order to understand the effect of the Zn/Mg ratio on age hardening behaviour in Al-Zn-Mg alloys. It was seen from hardness measurement that the peak hardness increased with increasing amount of Zn and Mg. Tensile tests were performed for the samples of peak aged condition. It was seen that UTS increased with increasing amount of the Zn and Mg. The elongation decreased with increasing the amount of the Zn and Mg. Intregranular fracture was observed in alloys with low amount of Zn and Mg.Transgranular fracture was observed with high amount of Zn and Mg alloy. TEM observation was performed for peak aged samples. The size of precipitates became finer and the number density increased with increasing Zn and Mg contents.T’ Phase and h1 phase were observed in low Zn/Mg alloy. The h’ phase was observed in high Zn/Mg alloy.

scholarly journals Quality Enhancement of TIG Welded Al6061 SiCp Composites by Age Hardening Process

2018 ◽  
Vol 15 (3) ◽  
pp. 5573-5582 ◽  
Author(s):  
M. C. G. Shankar ◽  
Jayashree P. K ◽  
S. S. Sharma ◽  
R. Shetty ◽  
K. Vinay
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Weld Zone ◽  
Weight Ratio ◽  
Substantial Improvement ◽  
Age Hardening ◽  
Peak Hardness ◽  
Specific Strength ◽  
Hardening Process ◽  
Peak Aged

Aluminium and its alloys have exceptional corrosion resistant properties, simplicity of fabrication and extraordinary specific strength-to-weight ratio. The main objective of this study is to explore the effect of age hardening on the mechanical properties of tungsten inert gas (TIG) welded joints of the composite. This study highlights the enrichment in mechanical properties like hardness and tensile strength of TIG welded Al6061-SiC composites. A single-pass TIG welding using 5356 filler material is carried out on the composite with varying percentages of SiC having 25 µm. The hardness and tensile strength of the weld zone in as-weld condition is measured. The samples are then subjected to age hardening treatment at different temperatures and the peak hardness values are determined. The tensile strength is noted, and these values are compared with the values of the as-weld condition. The microstructure of the fracture surface in as-weld and peak aged condition is taken and the type of failure mode is found out. X-ray diffraction (XRD) spectra of the peak-aged sample is also considered for the analysis. The results indicated that there was significant influence leading to substantial improvement of hardness and tensile strength values of the samples after the age hardening process.

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