Numerical Analysis of Semi-Solid Die-Casting Automobile Part Based on the Thermo-Visco-Plastic Constitutive Relation

2015 ◽  
Vol 1096 ◽  
pp. 268-274 ◽  
Author(s):  
Jiao Jiao Wang ◽  
Gui Min Lu ◽  
Jian Guo Yu
Keyword(s):  
Shear Rate ◽  
Aluminum Alloys ◽  
Apparent Viscosity ◽  
Volume Fraction ◽  
Die Casting ◽  
Solid Volume Fraction ◽  
Casting Process ◽  
Processing Parameters ◽  
Compression Tests ◽  
Semi Solid

Thermal simulation compression tests were performed on semi-solid billet in order to observe and investigate the behavior of 6061 aluminum alloys while varying the processing parameters such as apparent viscosity, the shear rate and the temperature. Specimens of 6061 aluminum alloys were characterized with their semi-solid behavior during partial melting and holding in the semi-solid state. Furthermore, the constitutive equation of semi-solid 6061 aluminum alloys was investigated. Moreover, the tests allow the apparent viscosity and shear rate of the alloys to be determined as a function of the solid volume fraction and strain rate together with the geometry behavior of the specimen. Utilizing these parameters, semi-solid die casting process of 6061 aluminum alloys could be simulated by the change of the solid volume fractions.

Constitutive Model of Thixotropic Plastic Forming for Semi-Solid AZ61 Magnesium Alloy

2006 ◽  
Vol 116-117 ◽  
pp. 639-642 ◽  
Author(s):  
Hong Yan ◽  
Bing Feng Zhou
Keyword(s):  
Magnesium Alloy ◽  
Volume Fraction ◽  
Testing Machine ◽  
Processing Parameters ◽  
Liquid Volume ◽  
Compression Tests ◽  
Liquid Volume Fraction ◽  
Az61 Magnesium Alloy ◽  
Az61 Alloy ◽  
Semi Solid

Uniaxial compression tests on semi-solid AZ61 alloy fabricated by stain-induced activation (SIMA) process and the conventional casts were carried out using the Gleedle-1500 dynamic material testing machine. The relationships between stress and stain were analyzed. The numerical relationships among processing parameters (strain rate z ε& strain z ε temperature T liquid volume fraction L f ) and stress were studied. The proposed constitutive equation was established for semi-solid AZ61 magnesium alloy using the multiple nonlinear regression method. A scientific basic provided for both numerical simulation of processing process of semi- solid AZ61 alloy and rational choice and control of processing parameters.

Microstructure and Mechanical Properties of Al Alloys by Semi-Solid Processing with LSPSF Technology

2009 ◽  
Vol 628-629 ◽  
pp. 477-482 ◽  
Author(s):  
Hong Min Guo ◽  
Xiang Jie Yang ◽  
J.X. Wang
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Die Casting ◽  
High Strength ◽  
Casting Process ◽  
Homogeneous Distribution ◽  
Casting Alloy ◽  
Die Casting Process ◽  
Casting Industry ◽  
Semi Solid

Rheoforming is becoming the choice of the casting industry which relies on the semi-solid slurry for high integrity structural parts. The potential of rheoforming with LSPSF (Low superheat pouring with a shear field) for aluminum alloys was investigated in the present work. High quality semi-solid slurries of a series of aluminum alloys were manufactured by LSPSF process, such as casting alloy A356, high strength alloy 201, secondary die casting alloy A380 and wrought alloy 2024, 6082 and 7075, in which the primary α-Al presented spherical, small and homogeneous distribution, especially with zero-entrapped liquid. Applications of LSPSF in high pressure die casting process and squeeze casting process were presented. Results showed that LSPSF rheoforming could improve microstructures and increase mechanical properties.

Effect of solid fraction on formability and mechanical properties in a vertical-type rheo squeeze-casting process

2011 ◽  
Vol 225 (2) ◽  
pp. 184-196
Author(s):  
S M Lee ◽  
C G Kang
Keyword(s):  
Solid Fraction ◽  
Squeeze Casting ◽  
Volume Fraction ◽  
Die Casting ◽  
Solid Volume Fraction ◽  
Casting Process ◽  
Spherical Particles ◽  
Forming Process ◽  
Dendritic Microstructure ◽  
Squeeze Casting Process

This paper demonstrates an electromagnetic stirring (EMS) process which strongly stirs the molten metal at the initial stage of solidification, in order to transform the dendritic microstructure into fine spherical particles close to a globule; the paper accordingly suggests that the vertical squeeze-casting process is suitable for forming rheological material into engineering parts. Thus, this study investigates the performance of the vertical rheological die-casting process for developing highly functional and lightweight engineering parts. The vertical squeeze-casting process was optimized to obtain a high-quality product by controlling the solid volume fraction through EMS, as well as the velocity of injection in the rheological forming process; subsequently, the formability of the product was estimated. As a result, the mechanical characteristics of the product fabricated for each condition could be examined. In this study, the channel type of product was selected because of its feasibility to be adapted to a vehicle component of rheological materials. It is suggested that when rheological materials formed by the EMS process, which controls the solid fraction of rheological material, are manufactured into engineering components by vertical die-casting, the fine microstructure of the product can be fabricated.

scholarly journals Quantification of shear viscosity and wall slip velocity of highly concentrated suspensions with non-Newtonian matrices in pressure driven flows

2021 ◽  
Author(s):  
Patrick Wilms ◽  
Jan Wieringa ◽  
Theo Blijdenstein ◽  
Kees van Malssen ◽  
Reinhard Kohlus
Keyword(s):  
Shear Stress ◽  
Liquid Phase ◽  
Shear Rate ◽  
Shear Viscosity ◽  
Slip Velocity ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Wall Slip ◽  
Flow Index ◽  
Concentrated Suspensions

AbstractThe rheological characterization of concentrated suspensions is complicated by the heterogeneous nature of their flow. In this contribution, the shear viscosity and wall slip velocity are quantified for highly concentrated suspensions (solid volume fractions of 0.55–0.60, D4,3 ~ 5 µm). The shear viscosity was determined using a high-pressure capillary rheometer equipped with a 3D-printed die that has a grooved surface of the internal flow channel. The wall slip velocity was then calculated from the difference between the apparent shear rates through a rough and smooth die, at identical wall shear stress. The influence of liquid phase rheology on the wall slip velocity was investigated by using different thickeners, resulting in different degrees of shear rate dependency, i.e. the flow indices varied between 0.20 and 1.00. The wall slip velocity scaled with the flow index of the liquid phase at a solid volume fraction of 0.60 and showed increasingly large deviations with decreasing solid volume fraction. It is hypothesized that these deviations are related to shear-induced migration of solids and macromolecules due to the large shear stress and shear rate gradients.

Development of Semi-Solid Die Casting Product Design and Die Design Technology for Aluminium Alloy Clamp

2016 ◽  
Vol 256 ◽  
pp. 334-339 ◽  
Author(s):  
Song Chen ◽  
Fan Zhang ◽  
You Feng He ◽  
Da Quan Li ◽  
Qiang Zhu
Keyword(s):  
Product Design ◽  
Die Casting ◽  
Casting Process ◽  
Die Design ◽  
Thick Wall ◽  
Thin Wall ◽  
Gating System ◽  
Cross Sectional ◽  
Die Casting Process ◽  
Semi Solid

Semi-solid slurry has significantly higher viscosity than liquid metal. This character of fluidity makes product design and die design, such as gating system, overflow and venting system, be different between these two die casting processes. In the present paper, taking a clamp product as an example, analyses the product optimization and die design by comparing the experimental and computational numerical simulation results. For the clamp, product structure is designed to be suitable for characters of SSM die casting process. The gating system is designed to be uniform variation of thickness, making the cross-sectional area uniformly reduce from the biscuit to the gate. This design ensures semi-solid metal slurry to fill die cavity from thick wall to thin wall. Gate position is designed at the thickest location, the gate shape of semi-solid die casting is set to be much bigger than traditional liquid casting. A good filling behaviour can be achieved by aforementioned all these design principles and it will be helpful to the intensification of pressure feeding after filling.

Development of 2-Cavity Die Casting Process for AM50 Mg Steering Column Lock Housing Module

2006 ◽  
Vol 510-511 ◽  
pp. 334-337
Author(s):  
Shae K. Kim
Keyword(s):  
Magnesium Alloy ◽  
Aluminum Alloys ◽  
Magnesium Alloys ◽  
Weight Reduction ◽  
Die Casting ◽  
Casting Process ◽  
Research Strategy ◽  
Good Choice ◽  
Weight Basis ◽  
Die Casting Process

It is obvious that automotive industry worldwide is predicting significant growth in the use of magnesium alloys for weight reduction to decrease fuel consumption and emission. About a half decade ago, the price of magnesium alloys was more than twice that of aluminum alloys on a weight basis. Currently, magnesium alloys cost about one and a half times that of aluminum alloys on a weight basis, and thus the price of magnesium alloys is the same as or lower than that of aluminum alloys on a per volume basis. However, in considering the performance of magnesium components (not their specific mechanical properties) and recycling aspect of magnesium alloys, it is required to realize niche applications of magnesium alloys, which meet the cost requirement on performance basis and/or offer more than weight reduction. There are many other factors that make magnesium a good choice: component consolidation, improved safety for driver and passengers, and improved noise vibration and harshness (NVH), to name a few. As one of these efforts to adopt magnesium alloys in automotive component, this paper describes the research strategy of cold chamber type 2-cavity die casting of AM50 magnesium alloy for developing the steering column lock housing module with emphasis on cost driving factors and necessities for cost reduction, explaining why AM50 magnesium alloy is chosen with design and die casting process optimization.

Continuous Casting of Magnesium Billets for Semi-Solid Processing

2005 ◽  
Vol 475-479 ◽  
pp. 517-520
Author(s):  
Hwa Chul Jung ◽  
Kwang Seon Shin
Keyword(s):  
Aluminum Alloys ◽  
Continuous Casting ◽  
Magnesium Alloys ◽  
Casting Process ◽  
Az91 Alloy ◽  
Attractive Alternative ◽  
Limited Information ◽  
Continuous Casting Process ◽  
Dendritic Microstructure ◽  
Semi Solid

Semi-solid processing is recognized as an attractive alternative method for the near net-shape production of engineering components. Although there has been a significant progress in semi-solid processing of aluminum alloys, very limited information is available on semi-solid processing of magnesium alloys, except for the thixomolding process. Continuous casting process has been utilized to produce the billets with the desirable cross-section at a reduced production cost for many metals, such as steel, copper and aluminum alloys. It has also been commercially utilized to produce the aluminum billets with non-dendritic microstructure for subsequent thixocasting process. However, continuous casting of magnesium billets for semi-solid processing has not yet been commercialized due to the difficulties involved in casting of magnesium alloys. In the present study, a continuous casting process has been developed for the production of the cylindrical billets of magnesium alloys for the subsequent thixocasting process. In order to obtain the desired non-dendritic microstructure with an excellent degree of homogeneity both in microstructure and composition, an electromagnetic stirring system has been utilized. A continuous casting process has been proven to be an efficient way to produce the high quality billets of magnesium alloys for semi-solid processing. A prototype air conditioner cover was produced using the continuously cast billets of AZ91 alloy.

Die Design for Main Bearing Cap of Engine Block Based Semi-Solid Die Casting Process and the Comparison Analysis with Squeeze Casting Process

2019 ◽  
Vol 285 ◽  
pp. 429-435 ◽  
Author(s):  
Song Chen ◽  
Da Quan Li ◽  
Fan Zhang ◽  
Min Luo ◽  
Xiao Kang Liang ◽  
...  
Keyword(s):  
Squeeze Casting ◽  
Die Casting ◽  
Dendritic Structure ◽  
Casting Process ◽  
Die Design ◽  
Main Bearing ◽  
Block Based ◽  
Semi Solid ◽  
Bearing Cap ◽  
Squeeze Casting Process

There are two new processes to development automobile structural components which have certain thickness. In the present paper, taking a main bearing cap product as an example, analyses die design by comparing the experimental and computational numerical simulation results. For the main bearing cap, product structure and mold design were designed to be suitable for characters of SSM die casting and squeeze process. Semi-solid slurry has significantly higher viscosity than liquid metal. This character of fluidity and solid fraction phase make the flow condition more laminar than liquid squeeze casting with the partial fill experiment. And compared with squeeze casting process, the globular shape grain size is smaller than dendritic structure. And mechanical property result shows that the elongation of SSM die casting can achieve more than twice than squeeze casting.

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