Thixoforming and Industrial Application of the Semi-Solid Alloy Al-6Si-2Mg

2006 ◽  
Vol 116-117 ◽  
pp. 72-75 ◽  
Author(s):  
Li Jun Xie ◽  
Jun Xu ◽  
Bi Cheng Yang ◽  
Zhi Feng Zhang ◽  
Li Kai Shi
Keyword(s):  
Heat Treatment ◽  
Continuous Caster ◽  
Die Casting ◽  
Electromagnetic Stirring ◽  
Solid Alloy ◽  
Fraction Solid ◽  
Casting Unit ◽  
Fine Microstructure ◽  
Automobile Components ◽  
Semi Solid

An application of the semi-solid alloy Al-6Si-2Mg to produce automobile components was carried out for farther development of this new alloy. The experiments were done in a self-developed SSM trial line composed of semi-continuous caster combined with electromagnetic stirring for feedstock billet production, 6-station induction reheating equipment for restoring thixotropy of SSM billet and modified die-casting unit for semi-solid thixoforming. The results show that Al-6Si-2Mg alloy has such a suitable fraction solid and low temperature sensitivity of fraction solid that the controllability of SSM process is increased greatly. The billets have uniformly fine microstructure with a higher degree of sphericity and also retain good thixotropic properties. During thixoforming, the die is filled completely, the microstructure of components is dense, and the primary phases are near spherical, and the mechanical property after heat treatment has good performance.

Tensile Properties of Semi-Solid Die Cast AC4C Aluminum Alloy

2014 ◽  
Vol 680 ◽  
pp. 11-14
Author(s):  
Ke Ren Shi ◽  
Sirikul Wisutmethangoon ◽  
Jessada Wannasin ◽  
Thawatchai Plookphol
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Die Casting ◽  
Casting Process ◽  
Al Alloy ◽  
Die Cast ◽  
Die Casting Process ◽  
Semi Solid ◽  
Strength And Ductility

In this study, semi-solid Al-Mg-Si alloy (AC4C) was produced by using the Gas Induced Semi-Solid (GISS) die casting process. The tensile strength and ductility of the semi-solid die cast Al alloy (GISS-DC) after T6 heat treatment were investigated and compared with those of the conventional liquid die casting (CLDC). The microstructures of GISS-DC and CLDC observed by an optical microscopy were presented. The ultimate tensile strength (UTS) and yield strength (0.2% YS) of GISS-DC are compatible with those of the CLDC. However, the GISS-DC has better ductility than the CLDC, this may be due to the smaller and more globular primary α-Al phase and rounder shaped-Si particle microstructures presented in the GISS-DC. Common shrinkage pores and defects were also observed by SEM from the fracture surfaces of both alloys.

Research on Microstructure and Mechanical Properties Evolution of Rheocast and Thixocast 319s Aluminum Alloy

2016 ◽  
Vol 850 ◽  
pp. 802-808 ◽  
Author(s):  
Kang Du ◽  
Xiao Kang Liang ◽  
Da Quan Li ◽  
Qiang Zhu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Treatment Time ◽  
Eutectic Silicon ◽  
Solution Treatment ◽  
Treatment Temperature ◽  
Solid Alloy ◽  
Obvious Effect ◽  
Higher Temperature ◽  
Semi Solid

In semi-solid rheocast and thixocast industry, T6 heat treatment was one key factor to improve the mechanical properties of the castings. The microstructure evolution was closely influenced by heat treatment temperature and time. In this paper, the morphology change of eutectic silicon in semi-solid alloy during different heat treatment time was firstly observed. The changes of both roundness and aspect show that the silicon particles underwent fragmentation, coarsening and growing up processes during solution treatment. Then, the mechanical properties after stand T6 and T6 with higher temperature were compared. It may be concluded that the higher temperature doesn’t have obvious effect to increase the mechanical strength, but severe negative effect on the elongation. Finally, the incipient melting defect appeared in higher temperature T6 was proved and its relationship with elongation was analysed.

Application of Multiphase Modelling in Semi-Solid Die Casting: Blister Prediction

2016 ◽  
Vol 256 ◽  
pp. 139-145 ◽  
Author(s):  
Xiao Gang Hu ◽  
Qiang Zhu ◽  
Helen V. Atkinson ◽  
Min Luo ◽  
Fan Zhang ◽  
...  
Keyword(s):  
Solid Phase ◽  
Die Casting ◽  
Phase Segregation ◽  
Casting Process ◽  
Alloy System ◽  
Design Tool ◽  
System Modelling ◽  
Solid Alloy ◽  
Homogeneous Fluid ◽  
Semi Solid

One-phase modelling is widely used as an optimization and design tool for semi-solid casting process. By this approach, semi-solid alloy is taken as a homogeneous fluid and flow behaviours are represented by using the rheological properties of the mixture. A single set of conservation equations is solved to simulate the mould filling, without considering the different motilities between the liquid and the solid phase. Therefore, defects due to phase segregation cannot be predicted and particle tracking cannot be carried out. This study is focused on multiphase (i.e. a liquid-particle-air system) modelling during the semi-solid filling process of a thin-walled component. By using this approach, the solid phase is treated as a power law fluid and the phase interactions among the phases are introduced for the semi-solid alloy system. Practical semi-solid die casting is carried out for verification of phase segregation. The final distribution of air is calculated and proved by practical blistering examination. The simulation results are verified to be accurate in a reasonable range, indicating an approach for modelling semi-solid filling including the formation (and avoidance) of blisters.

Effect of Slurry Temperature Distribution on Semi-Solid Die Casting

2016 ◽  
Vol 256 ◽  
pp. 107-112 ◽  
Author(s):  
Wen Ying Qu ◽  
Fan Zhang ◽  
Jiao Jiao Wang ◽  
Xiao Gang Hu ◽  
Qiang Zhu
Keyword(s):  
Temperature Distribution ◽  
Die Casting ◽  
Casting Process ◽  
Flow Patterns ◽  
Solid Alloy ◽  
Filling Process ◽  
Air Entrapment ◽  
Die Filling ◽  
Die Casting Process ◽  
Semi Solid

Semi-solid alloy slurries with different temperature distributions have diverse flow patterns of the slurries during die casting filling process. This different flow patterns can lead to various degrees of front separation of the slurry metal from the die cavity during die filling process. This separation can result in air entrapment, which is one of the origins for gas porosities and blisters occurred during followed heat treatment. Therefore, in this paper, the effects of slurry temperature distribution on filling patterns during die casting process were investigated. Based on partial filling experiments, positive and negative gradient temperature distribution, together with two homogeneous conditions 575°C, 579°C were compared by computer simulation. The results indicate that the positive gradient temperature condition of 357.0 slurry is more suitable for the semi-solid die casting of the connector, and 7 °C temperature gradient in slurry is appropriate for good filling.

scholarly journals Comparison of the Heat Treatment Response of SSM-HPDC 6082 and 6004 Wrought Alloys with A356 and F357 Casting Alloys

2011 ◽  
Vol 690 ◽  
pp. 53-56 ◽  
Author(s):  
Heinrich Möller ◽  
Gonasagren Govender ◽  
Waldo Stumpf
Keyword(s):  
Heat Treatment ◽  
Artificial Aging ◽  
Die Casting ◽  
Natural Aging ◽  
Solid Metal ◽  
Casting Alloys ◽  
Aging Response ◽  
Semi Solid ◽  
Si Content ◽  
Pressure Die Casting

Semi-solid metal high pressure die casting was used to produce plates from traditional wrought Al-Mg-Si alloys 6082 and 6004, as well as from traditional casting Al-Si-Mg alloys A356 and F357. The high Si-content of the casting alloys offer several advantages, including a faster artificial aging response, higher strength for comparable Mg contents and less sensitivity to prior natural aging on peak strength. However, over-aging occurs earlier in the casting alloys than in the wrought alloys.

THINCASTTM; Providing Strong, Lightweight Castings for Automobiles and Other Applications

2014 ◽  
Vol 217-218 ◽  
pp. 294-301
Author(s):  
Alois Franke ◽  
John L. Jorstad
Keyword(s):  
Heat Treatment ◽  
High Pressure ◽  
Die Casting ◽  
Casting Process ◽  
Engineering Properties ◽  
Traditional Process ◽  
Semi Solid ◽  
Die Castings ◽  
New Applications

Aluminium Rheinfelden has improved the competitiveness of semi solid processing by developing a casting process & alloy combination that is capable of ultra thin, ultra light parts having attractive engineering properties without need for full heat treatment. The THINCASTTM rheocasting process, together with Rheinfeldens Magsimal-59 alloy has been demonstrated capable of producing moderate sized castings with only 1-2 mm wall sections, thus providing a 30-50% reduction in traditional-process part weight. THINCASTTM can be adapted to a variety of die casting machines and will enable competitively improving the quality of conventional high pressure die castings as well as creating entirely new applications.

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.

Control of Amount of α-Al Phase Particles in near Eutectic Al-Si Alloy by Electromagnetic Stirring

2022 ◽  
Vol 327 ◽  
pp. 250-254
Author(s):  
Yuichiro Murakami ◽  
Naoki Omura
Keyword(s):  
Solid State ◽  
Volume Fraction ◽  
Electromagnetic Stirring ◽  
Casting Alloy ◽  
Slow Cooling ◽  
Fraction Solid ◽  
Three Phase ◽  
Rotational Magnetic Field ◽  
Semi Solid ◽  
Si Content

Al-Si alloy is widely used as a casting alloy. The α-Al phase in the semi-solid state has low Si content in the Al-Si alloy. Then by separation of these α-Al phases from semi-solid Al-Si alloy, refining of aluminum can be possible. But, in near eutectic Al-Si alloy, few primary α-Al phases can be crystallized. If the fraction ratio of the α-Al phase can be increased, near eutectic Al-Si alloy can refine, and this method can be used for recycling. In this study, the effect of electromagnetic stirring (EMS) on the microstructure, especially the amount of the α-Al phase particles was investigated. A rotational magnetic field was applied to JIS ADC12 alloy which has near eutectic content during slow cooling from the liquid state to the solid-state, by using a three-phase AC coil. By applying EMS at solidification, the shape of the α-Al phase became particle shape from dendrite shape, and the amount of α-Al phase particles was increased. Moreover, by applying unidirectional intermittent EMS, the volume fraction of α-Al phase particles was decreased with increasing intermittent applying time. In ADC12 alloy, the primary α-Al phases can be crystallized only 10% generally, but it could be obtained over 40% by applying EMS. This means that the semi-solid slurry of near eutectic alloy with over 40% of fraction solid can be obtained by applying EMS.

Determination of Die Design Rules for Semi-Solid Die Casting Process and Its Experimental Investigation

2005 ◽  
Vol 475-479 ◽  
pp. 2533-2538 ◽  
Author(s):  
Chung Gil Kang ◽  
P.K. Seo ◽  
Byung Min Kim
Keyword(s):  
Heat Treatment ◽  
Die Casting ◽  
Casting Process ◽  
Die Design ◽  
Design Rule ◽  
Gating System ◽  
T6 Heat Treatment ◽  
Semi Solid ◽  
Line Design ◽  
Air Vent

Die design rule for semi-solid die casting (SSDC) with A356 electromagnetic stirring (EMS) aluminum alloy, was proposed. The die design rule included inspection of machine, part requirements, parting line determination, sleeve, plunger, gating system, overflow, air vent, ejector pin, and heating line design. The specification of gating system, overflow, air vent, plunger tip, and sleeve suitable for respective part were regulated. Two steps die system of lower-positioned gate and three steps die system of center-positioned gate were manufactured for 4 automobile suspension parts, based on the die design rule. For the sound filling pattern and solidification behavior, injection speeds of 4 parts were summarized to the interval (from V1 to V4). As a result of observing the microstructure of 4 parts after T6 heat treatment, primary Al-α phase was globularized and fine Si particles were distributed around the grain boundary. The mechanical properties of 4 parts with T6 heat treatment were investigated and showed ultimate tensile strength (UTS) of 330 MPa, yield strength (YS) of 250 MPa, and elongation of 7.5% as average.

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