The Experts below are selected from a list of 52539 Experts worldwide ranked by ideXlab platform
Brian Ralph - One of the best experts on this subject based on the ideXlab platform.
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A reclassification of the Die-filling stages in Pressure Die-casting processes
Journal of Materials Processing Technology, 1996Co-Authors: Y. B. Lui, Bun Lee, Brian RalphAbstract:Abstract Traditionally, the Die-filling process in Pressure Die-casting is divided into three stages. This paper initiates the concept of a ‘five-stage’ process for one-shot Pressure Die-casting processes. The concept of a ‘five-stage’ process retains the familiar first and second stages, breaks down the third stage into two and adds a fifth ‘residual stage’. It is shown that the maximum metal Pressure developed at the end of the fourth stage represents the compressibility of the molten metal and the hydraulic oil. Equations for the dynamic Pressures during the fourth stage are derived. There is still a lack of information on the bulk modulus of various molten metals. From the equations derived, an experimental method for the determination of the bulk modulus of molten metal is suggested. The analysis of the five stages, which links the metal feed system with the fluid-power main circuit of the Die-casting machine, gives a set of mathematical models for tackling the problem in question.
Gary Savage - One of the best experts on this subject based on the ideXlab platform.
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Performance Evaluation of High-Pressure Die-Cast Magnesium Alloys
The Minerals Metals & Materials Series, 2017Co-Authors: Mark Alan Easton, Su-ming Zhu, Mark A. Gibson, Trevor B. Abbott, Hua Qian Ang, Xiaobo Chen, Nick Birbilis, Gary SavageAbstract:Over 90% of the magnesium (Mg) alloys in commercial applications are produced by high-Pressure Die-casting. This paper presents our efforts in evaluating castability and properties of commercial and near-commercial magnesium alloys to demonstrate how the currently available alloys can be applied to different situations across a range of property space. For high temperature applications, i.e. 175 °C and above, Mg–RE and Mg–Al–Ca based alloys have creep properties at least comparable to aluminium (Al) alloy A380 although these alloys have some challenges with casting or cost. For moderate temperatures, Mg–Al–RE based alloys, especially AE44, are most attractive due to an excellent combination of creep resistance, strength and castability. For automotive structural applications where a good combination of strength and ductility is required, Mg–Al alloys provide the baseline, but Mg–Al–RE based alloys can provide outstanding performance, especially with recent discoveries about its response to age hardening treatments. Therefore, high-Pressure Die-cast Mg alloys hold great promise for continued growth in automotive applications.
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Gas content in high Pressure Die castings
Journal of Materials Processing Technology, 2011Co-Authors: Laihua Wang, Peter Turnley, Gary SavageAbstract:This paper presents the results of a quantitative study of the gas level in various types of castings from the high Pressure Die casting (HPDC) process using a vacuum fusion method. It was found that the major part of the gas was from the air entrapment during cavity filling. Other sources such as air entrapment during ladling, residual Die lubricant and quenching water were also noticeable. Measurements of a large casting and castings from a multi-cavity Die showed that the gas content was unevenly distributed. The modified vacuum fusion method has been proved to be a valuable tool for evaluating and quantifying the level of gas in castings as well as for an assessment of the influence of different process parameters on gas evolution in castings.
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Evaluation of castability of high Pressure Die cast magnesium based alloys
International Journal of Cast Metals Research, 2010Co-Authors: Katharina Strobel, Mark Alan Easton, Mark A. Gibson, Gary Savage, Vinay Kumar Tyagi, Morris Murray, Trevor B. AbbottAbstract:AbstractAlloy characteristics that impact on castability, such as hot tearing and fluidity, are as significant to the success of an alloy development program as the mechanical properties requirements of the final component. However, castability is often overlooked in the alloy development process and this could lead to substantial problems in fabrication. A new Die has been developed to test multiple indicators of the high Pressure Die castability of an alloy. A rating system has been introduced to evaluate several exterior quality factors for high Pressure Die castings. This is coupled with selected metallographic inspection of the interior defects and the results are combined to compare the relative performance of different alloys. It was found that ZA124 alloy was the most castable of the alloys tested followed by AZ91 with the castability decreasing with decreasing Al content for Mg–Al based alloys.
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Thermal and flow modelling of ladling and injection in high Pressure Die casting process
International Journal of Cast Metals Research, 2003Co-Authors: Laihua Wang, Gary Savage, Thang Nguyen, Cameron DavidsonAbstract:Air entrapment and premature solidification in the shot sleeve of the cold chamber high Pressure Die casting process are problems affecting the casting quality. These issues are addressed from seve...
Y. B. Lui - One of the best experts on this subject based on the ideXlab platform.
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A reclassification of the Die-filling stages in Pressure Die-casting processes
Journal of Materials Processing Technology, 1996Co-Authors: Y. B. Lui, Bun Lee, Brian RalphAbstract:Abstract Traditionally, the Die-filling process in Pressure Die-casting is divided into three stages. This paper initiates the concept of a ‘five-stage’ process for one-shot Pressure Die-casting processes. The concept of a ‘five-stage’ process retains the familiar first and second stages, breaks down the third stage into two and adds a fifth ‘residual stage’. It is shown that the maximum metal Pressure developed at the end of the fourth stage represents the compressibility of the molten metal and the hydraulic oil. Equations for the dynamic Pressures during the fourth stage are derived. There is still a lack of information on the bulk modulus of various molten metals. From the equations derived, an experimental method for the determination of the bulk modulus of molten metal is suggested. The analysis of the five stages, which links the metal feed system with the fluid-power main circuit of the Die-casting machine, gives a set of mathematical models for tackling the problem in question.
Peter Hodgson - One of the best experts on this subject based on the ideXlab platform.
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Integrated optimization system for high Pressure Die casting processes
Journal of Materials Processing Technology, 2007Co-Authors: Lingxue Kong, Fengshua She, Weimin Gao, Saeid Nahavandi, Peter HodgsonAbstract:High Pressure Die casting (HPDC) is a versatile process for producing engineered metal parts by forcing molten metal under high Pressure into reusable steel Dies. However there are a large number of attributes involved which contribute to the complexity of the process. A novel integrated approach is developed to optimize the high Pressure Die casting processes. The Die temperature profiles will be stuDied with infrared thermograph technology and the internal cooling system will be optimized to provide even cooling to the components and the Die. The heat stored in the Die and the components is stuDied with image processing. Based on the geometrical profile of the components, cooling channels can be redesigned to improve the cooling efficiency while the cooling time is reduced. This will not only significantly improve the quality of the castings but also improve the productivity of the process.
A. Sreeranganathan - One of the best experts on this subject based on the ideXlab platform.
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Reconstruction and visualization of complex 3D pore morphologies in a high-Pressure Die-cast magnesium alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2006Co-Authors: Soon Gi Lee, Arun M. Gokhale, A. SreeranganathanAbstract:Abstract Visualization and representation of three-dimensional (3D) pore morphologies in the high-Pressure Die-cast Mg alloys are of significant interest for understanding and modeling processing–microstructure–properties relationships. In this contribution, an efficient and unbiased montage serial sectioning technique is applied for reconstruction of large volume (∼1.24 × 10 9 μm 3 ) high-resolution (∼1 μm) 3D microstructure of a high-Pressure Die-cast AM50 Mg alloy containing gas (air) and shrinkage pores. The reconstruction of 3D microstructure from montage serial sections enables visualization and characterization of detailed 3D morphologies and spatial correlations of gas (air) and shrinkage pores. The reconstructed 3D microstructure is implemented in a 3D finite elements (FE) computational framework to illustrate how realistic complex microstructural feature morphologies can be incorporated in the simulations of micromechanical response of these high-Pressure Die-cast cast microstructures.
