The Effect of Solution Time on the Microstructure of A356.2 Aluminum Alloy Provided by Rheocasting and Squeeze Casting

2022 ◽  
Vol 327 ◽  
pp. 189-196
Author(s):  
Le Cheng ◽  
Hong Xing Lu ◽  
Min Luo ◽  
Xing Gang Li ◽  
Wan Peng Zhang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Solution Heat Treatment ◽  
Production Efficiency ◽  
Treatment Process ◽  
Squeeze Casting ◽  
Solution Process ◽  
Solution Treatment ◽  
Solution Time ◽  
Conventional Solution ◽  
Short Time

The evolution of the microstructure of A356.2 alloys prepared by the rheocasting and squeeze casting during solution heat treatment was investigated. In contrast with the conventional solution heat treatment process (3 hours at 540oC), a short time solution treatment process (less than 1 hour at 540oC) is applied in this paper. The results show that the rheocastings require a shorter solution time than the squeeze-castings to obtain spheroidized Si particles. After solution for 10 min, the X-ray diffraction inspection results show that the Mg2Si phase completely is dissolved in both rheocastings and squeeze-castings. However, a small amount of Mg2Si is found at the edge of the Si particle by scanning electron microscope observation. After solution for more than 20 min, the Mg2Si phase is completely dissolved. Fe-rich phases, including AlSiFeMg and AlFeSi, exist throughout the solution process. The developed T6 heat treatment with a short solution time can effectively improve production efficiency and decrease process cost for the rheocasting process. Key words: A356.2 alloy, microstructure, short solution time, rheocasting, squeeze casting

scholarly journals Evaluation of AA6061-T6 behavior subjected to Cyclic Solution Treatment

2020 ◽  
Vol 23 (4) ◽  
pp. 383-387
Author(s):  
Najmuldeen Yousif Mahmood ◽  
Ahmed Ameed Zainulabdeen ◽  
Jabbar Hussein Mohmmed ◽  
Hasanain Abd Oun
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Tensile Test ◽  
Aging Time ◽  
Vickers Hardness ◽  
Solution Heat Treatment ◽  
Treatment Process ◽  
Solution Treatment ◽  
Heat Treatment Process ◽  
Precipitate Phase

The effects of the repeated solution heat treatment on hardness, tensile strength and microstructure of aluminum were studied. For this purpose, an alloy of AA6061-T6 was undergo to cyclic solution heat treatment process which is composed of repeated period (10 min) held at 520 °C for 1, 4, 8 and 12 cycles. The hardness was tested for five aging times (as quenching, one week, three weeks, one month and five months) to all cycles (1, 4, 8 and 12) firstly and it is found that the hardness of five months as aging time for all cycles has the best results (90Hv) as compared with others (as quenching, one week, three weeks, and one month), so it was adopted for all cycles to implement the tensile test and the microstructure. Hardness results were improved to Vickers hardness of (90Hv) with increasing of cycles up to 8 cycles then decreasing after that to (45Hv). Tensile results were showed an increment (34%) also for the same group of 8 cycles compared with (17%) and (9%) for 4 and 12 cycles, respectively. Microstructure is revealed that whenever cycles are increased, the precipitate phase in alloy is increased also, thus, it is improved the hardness and tensile strength.

Effect of Heat Treatment on the Structure and Properties of EW75 Magnesium Alloy Plate

2013 ◽  
Vol 747-748 ◽  
pp. 158-165
Author(s):  
Juan Qu ◽  
Kui Zhang ◽  
Ming Long Ma ◽  
Yong Jun Li ◽  
Xing Gang Li
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Tensile Strength ◽  
Solution Process ◽  
Solution Time ◽  
Solution Temperature ◽  
Second Phase ◽  
Alloy Plate ◽  
T6 Heat Treatment ◽  
The Matrix

In this study, Mg-7Gd-5Y-1Nd-0.5Zr alloy (EW75) was produced by melting method and then press-forged into large size plate. The properties of the Mg-7Gd-5Y-1.2Nd-0.5Zr alloy were optimized through T6 heat treatment. The microstructures of alloy were observed by means of optical microscopy (OM), scanning electron microscopy (SEM). Its mechanical properties under different heat treatment conditions were determined by tensile tests. The results indicated that increasing the solid solution temperature and prolonging the solid solution time can both lead to the dissolution of second phase in the alloy back into the matrix. The solid solution temperature affects the dissolution process more than the solid solution time. Grain growth occurred during the solid solution process. The grain size of the matrix enlarges with the increase of solid solution temperature. The tensile test result showed that the tensile strength of the alloy was significantly improved after T6 heat treatment. Its tensile strength in the same direction was nearly 40% up after T6 heat treatment. The analysis shows that T6 heat treatment can effectively eliminate the larger deformed precipitates and beneficial to the formation of hard precipitates, which leads to an improvement in the alloys tensile strength.

Discussion and Improvement of Carburizing Defects

2013 ◽  
Vol 385-386 ◽  
pp. 27-29
Author(s):  
Yue Ying Liu ◽  
Xiu Hua Gao ◽  
Huan Na Li
Keyword(s):  
Heat Treatment ◽  
Production Efficiency ◽  
Treatment Process ◽  
Surface Hardness ◽  
Heat Treatment Process ◽  
Layer Depth ◽  
Part Surface ◽  
Carburized Layer ◽  
The Difference

mproving of the heat treatment process for carburizing bushing,Using the new charging rack for the bushing to solve the problems about the difference of the carburized layer depth on part surface, hardness uneven after heat treatment. At the same time, the production efficiency is also improved.

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.

Effect of the Two-Step Solution Heat Treatment on the Microstructure of Semisolid Cast 7075 Aluminum Alloy

2012 ◽  
Vol 488-489 ◽  
pp. 243-247 ◽  
Author(s):  
Saowalak Kongiang ◽  
Thawatchai Plookphol ◽  
Jessada Wannasin ◽  
Sirikul Wisutmethangoon
Keyword(s):  
Heat Treatment ◽  
Treatment Condition ◽  
Solution Heat Treatment ◽  
Solution Treatment ◽  
Heat Treatment Condition ◽  
Single Step ◽  
Eutectic Phase ◽  
Solution Treated ◽  
The Matrix ◽  
Black Particle

Effect of the two-step solution heat treatment on the microstructure of semisolid cast 7075 aluminium alloy has been studied. The microstructure of the as-cast specimens mainly consisted of matrix-α (Al) and grain boundary (GB)-eutectic phase (α-Al + Mg(Zn,Cu,Al)2). After solution treating, coarse black particles were found to form in the single-step solution treated specimens at the condition of 450 °C for 8 h and 480 °C for 1 h, respectively. Two-step solution heat treatment resulted in the reduction of coarse black particle formation while maintaining the same amount of eutectic MgZn2phase dissolution as the high temperature single-step solution treatment. Therefore, the two-step solution heat treatment enables alloying elements dissolved into the matrix without overheating and hence decreases coarse black particles. The optimum two-step solution heat treatment condition derived from this study was 400 °C for 8 h + 450 °C for 4 h.

scholarly journals The Effect of Cooling Rate after Homogenization on the Microstructure and Properties of 2017a Alloy Billets for Extrusion with Solution Heat Treatment on the Press

2016 ◽  
Vol 61 (3) ◽  
pp. 1663-1670
Author(s):  
A. Woźnicki ◽  
D. Leśniak ◽  
G. Włoch ◽  
P. Pałka ◽  
B. Leszczyńska-Madej ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cooling Rate ◽  
Solution Heat Treatment ◽  
Rapid Heating ◽  
The Press ◽  
Large Particles ◽  
Rapid Dissolution ◽  
Alloy Microstructure ◽  
Fast Dissolution ◽  
Short Time

AbstractThe influence of cooling rate after homogenization on the 2017A alloy microstructure was analysed. The capability of the θ (Al2Cu) particles, precipitated during various homogenization coolings, for rapid dissolution was estimated. For this purpose, the DSC test was used to determine the effect of the cooling rate after homogenization on the course of melting during a rapid heating. Moreover, the samples after solution heat treatment (with short time annealing) and ageing, were subjected to the microstructure investigations and the microhardness of grains interiors measurements. It was found that cooling after homogenization at 160 °C/h is sufficient for precipitation of fine θ phase particles, which dissolve during the subsequent rapid heating. The cooling at 40 °C/h, causes the precipitation of θ phase in the form of large particles, incapable of further fast dissolution.

Optimisation of the Solution Heat Treatment of Rheo-Processed Al-Cu-Mg-(Ag) Alloys A206 and A201

2009 ◽  
Vol 618-619 ◽  
pp. 353-356 ◽  
Author(s):  
E.P. Masuku ◽  
Heinrich Möller ◽  
R.D. Knutsen ◽  
L. Ivanchev ◽  
Gonasagren Govender
Keyword(s):  
Heat Treatment ◽  
Solution Heat Treatment ◽  
Solution Treatment ◽  
Dsc Analysis ◽  
Optimum Solution ◽  
Hardness Values

The traditional solution treatment cycles that are currently applied to rheo-processed A201 are mostly those that are used for conventional castings. These solution treatments are not necessarily the optimum solution treatments for rheo-processing. As a result, DSC analysis was done to optimize this heat treatment. The new solution treatment, which consists of higher temperatures and shorter times (515°C/5h, followed by 570°C/10h), resulted in slightly higher hardness values for both alloy A206 and A201.

Solution Heat Treatment of 7075 Aluminum Alloy Affected on Anodic Oxide Layer

2016 ◽  
Vol 867 ◽  
pp. 19-23 ◽  
Author(s):  
Itsaree Iewkitthayakorn ◽  
Somjai Janudom ◽  
Narissara Mahathaninwong
Keyword(s):  
Heat Treatment ◽  
Oxide Film ◽  
Solution Heat Treatment ◽  
Treatment Time ◽  
Solution Treatment ◽  
Secondary Phase ◽  
Anodic Oxide ◽  
Al Alloy ◽  
Heat Treated

This research focused on the effect of solution heat treated microstructures on anodic oxide formations of casting 7075 Al alloy. The casting specimens were solution heat treated at 450°C for various holding. The results showed that the quality of anodic oxide film on the specimen with 4h solution heat treatment time was higher than that of at other conditions. Because its microstructures obtained the lowest amounts of secondary phase particles leading to improve the quality of oxide film and also reduce defects in oxide film. On the other hand, coarse black particles of Mg2Si formed increasingly in microstructures of specimens after solution treatment at prolong holding time of 8h and 16h resulted in discontinues oxide films forming on them.

scholarly journals Mitigation of cylinder distortion in aluminum alloy engine blocks via heat treatment process optimization

2021 ◽  
Author(s):  
Anthony Lombardi
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Neutron Diffraction ◽  
Solution Heat Treatment ◽  
Treatment Process ◽  
Tensile Residual Stress ◽  
Engine Block ◽  
Engine Blocks ◽  
In Situ Neutron Diffraction

Lightweighting has become an important factor in the automotive industry due to stringent government regulations on fuel consumption and increased environmental awareness. Aluminum alloys are 65% lighter than cast iron enabling significant weight reduction. However, there are several significant challenges associated to the use of hypoeutectic Al-Si alloys in engine block applications. This dissertation investigated the factors influencing the susceptibility of in-service cylinder distortion as it is deleterious to engine operating efficiency, leading to environmental (increased carbon emissions) and economic (expensive recalls) repercussions. The initial segment of this dissertation sought to quantitatively confirm the cause of cylinder distortion by investigating distorted and undistorted service tested engine blocks. This analysis involved measurement of macro-distortion using a co-ordinate measuring machine, in-depth microstructural analysis, measurement of tensile properties, and residual stress mapping along the length of the cylinder bores (neutron diffraction). Upon determining the cause of distortion, the second phase of this project optimized the solution heat treatment parameters to mitigate future distortion in the engine blocks. This optimization was carried out by varying heat treatment parameters to maximize engine block strength. In addition, a pioneering application of in-situ neutron diffraction, along with a unique engine heating system, was used to develop a time-dependent correlation of residual stress relief during heat treatment, assisting in process optimization. The results indicate that the distorted engine block had high tensile residual stress, specifically at cylinder depths greater than 30 mm, while the undistorted block had mainly compressive stress. The maximum distortion occurred near the center portion of the cylinder (~60 mm), which had a combination of coarse microstructure (lower strength) and high tensile residual stress. As such,distortion can be prevented via maximization of strength and reduction in tensile residual stress. Lab scale castings and in-situ neutron diffraction were used to successfully develop an optimal heat treatment process to increase engine block integrity. These experiments found that solution heat treatment at 500 °C for 2 h increased tensile yield strength by 15-20% over engines produced using the current process. Furthermore, tensile residual stress was completely relieved by this heat treatment, reducing the susceptibility to in-service distortion. Solutionizing at temperatures above 500 °C was deemed unsuitable for engine block production due to incipient melting, which deteriorates strength.

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