Gas- and Shrinkage Porosities in Al-Si High-Pressure Die-Castings - Virtualization and Experimental Validation

2015 ◽  
Vol 364 ◽  
pp. 80-91
Author(s):  
Zenon Ignaszak ◽  
Jakub Hajkowski
Keyword(s):  
High Pressure ◽  
Experimental Validation ◽  
Mechanical Characteristics ◽  
Die Casting ◽  
Experimental Results ◽  
Matrix Structure ◽  
High Pressure Die Casting ◽  
The Matrix ◽  
Die Castings ◽  
Pressure Die Casting

The porosity (void caused by technological reasons) in engineering materials always decrease their mechanical characteristics and usually affects the deterioration of the functional mechanical characteristics of the finished products. In the castings the porosity resulting from the specific casting processes phenomena occurs inevitably in the matrix structure. The paper shows this problem in relation to the High-Pressure-Die-Casting (HPDC) technology of Al-Si alloy. The analysis of the experimental results and the results from virtualization of HPDC process allowed to assess the effectiveness of this mixed scenario and improve the quality predictions probability for HPDC, with particular consideration of shrinkage and gas porosities. The problem of the tolerance (admissibility) of porosity occurrence in castings and the castings made of liquid Al-Si alloy to which the gas (hydrogen) was introduced intentionally are signalized.

Integration of Piezoceramic Modules into Die Castings - Procedure and Functionalities

2008 ◽  
Vol 56 ◽  
pp. 170-175 ◽  
Author(s):  
Matthias Rübner ◽  
Carolin Körner ◽  
Robert F. Singer
Keyword(s):  
High Pressure ◽  
Die Casting ◽  
Structural Elements ◽  
High Pressure Die Casting ◽  
Sensor Actuator ◽  
Complete Integration ◽  
Mould Filling ◽  
Enhanced Properties ◽  
Die Castings ◽  
Pressure Die Casting

The complete integration of piezoceramic sensor/actuator-modules into metal components using high pressure die casting is a promising approach for the fabrication of multifunctional structural elements with enhanced properties. A technique providing stabilization and protection of the module during the highly dynamic mould filling is presented. Demonstration parts are produced which are fully capable to detect vibrations. An approach to characterize this sensory functionality of the adaptronic system is presented.

Application of a Novel Entrainment Defect Model to a High Pressure Die Casting

2014 ◽  
Vol 922 ◽  
pp. 801-806
Author(s):  
Robert Watson ◽  
Tayeb Zeguer ◽  
Simon Ruffle ◽  
William D. Griffiths
Keyword(s):  
High Pressure ◽  
Surface Film ◽  
Die Casting ◽  
Weibull Statistics ◽  
High Pressure Die Casting ◽  
Trapped Air ◽  
Mould Filling ◽  
Computational Fluid Dynamics Cfd ◽  
Die Castings ◽  
Pressure Die Casting

Aluminium High Pressure Die Castings are economical to produce in high volumes. However, as greater structural demands are placed on such castings, a more detailed understanding is required of the defects which limit their strength. The process is prone to high levels of surface turbulence and fluid break-up, resulting in the entrainment of air into the liquid metal, which may manifest as trapped air porosity or bifilm defects in the finished part. A novel algorithm was developed and integrated into a commercial computational fluid dynamics (CFD) package, to model mould filling, and the formation and transport of such entrainment defects. A commercial High Pressure Die Casting was simulated using this algorithm, to illustrate its application. Castings were also produced, and the results of tensile testing were summarised in the form of Weibull statistics. It was found that where the algorithm predicted a greater quantity of entrained surface film, a reduction in UTS of about 10% was also observed.

Effect of Temperature on the Properties of High Pressure Die Casting

2010 ◽  
Vol 649 ◽  
pp. 473-479 ◽  
Author(s):  
Jenő Dúl ◽  
Richárd Szabó ◽  
Attila Simcsák
Keyword(s):  
High Pressure ◽  
Data Acquisition ◽  
Die Casting ◽  
Data Acquisition System ◽  
Effect Of Temperature ◽  
High Pressure Die Casting ◽  
Die Castings ◽  
Pressure Die Casting ◽  
The Relationship

Quality of high pressure die castings is influenced by a lot of factors. Among them, the most important ones are the melt-, and die temperatures. This paper shows a data acquisition system, developed for measuring the melt and die temperatures and the results of the temperature measurements obtained under variable conditions. Evaluation of the relationship between the interrelated temperatures and the casting properties is based on analyzing the structure of the castings.

The Response of Entrainment Defect Distribution to Varied Fluid Flow Parameters in the High Pressure Die Casting of Al Alloys

2013 ◽  
Vol 765 ◽  
pp. 326-330
Author(s):  
Robert Watson ◽  
Tayeb Zeguer ◽  
Mike Buckley ◽  
Nick R. Green ◽  
Simon Ruffle ◽  
...  
Keyword(s):  
High Pressure ◽  
Fluid Flow ◽  
Fracture Stress ◽  
Die Casting ◽  
Sem Analysis ◽  
Service Reliability ◽  
High Pressure Die Casting ◽  
Cause Of Failure ◽  
Die Castings ◽  
Pressure Die Casting

High Pressure Die Casting is an economical means of manufacturing complex thin walled parts in high volumes. However, the process is prone to high levels of surface turbulence and fluid break-up, which results in the entrainment of bifilm defects. A study was carried out on a commercial casting to identify how changes in melt velocity and mould geometry affected the distribution of damaging bifilm defects, and the distribution of fracture stress. The statistical analysis of tensile test data indicated that two distinct defect populations existed; one of which caused relatively few failures, but often accounted for a large reduction in fracture stress when present. Where this defect population was not significant, Weibull moduli of 20 to 30 were achieved, comparable to sand castings with well-designed running systems. SEM fractography was also performed on a selection of samples to determine the probable cause of failure. A comparison of the SEM analysis to the statistical results indicated that bi-film defects initiated the fracture of those samples that failed at significantly lower stresses. Additionally, it was demonstrated that the geometric distribution of these cases was strongly correlated to changes in fluid flow conditions, suggesting that targeted modifications to mould geometry could increase the in-service reliability of High Pressure Die Castings.

scholarly journals Pressing Speed, Specific Pressure and Mechanical Properties of Aluminium Cast

2016 ◽  
Vol 16 (2) ◽  
pp. 45-50 ◽  
Author(s):  
S. Gaspar ◽  
J. Pasko
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Aluminum Alloy ◽  
Die Casting ◽  
High Pressure Die Casting ◽  
Technological Factors ◽  
Specific Increase ◽  
Die Castings ◽  
Pressure Die Casting ◽  
The Impact

Abstract Recent research in the process of aluminum alloy die castings production, which is nowadays deeply implemented into the rapidly growing automobile, shipping and aircraft industries, is aimed at increasing the useful qualitative properties of the die casting in order to obtain its high mechanical properties at acceptable economic cost. Problem of technological factors of high pressure die casting has been a subject of worldwide research (EU, US, Japan, etc.). The final performance properties of die castings are subjected to a large number of technological factors. The main technological factors of high pressure die casting are as follows: plunger pressing speed, specific (increase) pressure, mold temperature as well as alloy temperature. The contribution discusses the impact of the plunger pressing speed and specific (increase) pressure on the mechanical properties of the casting aluminum alloy.

Greenhouse Gas Emissions Attributable to High Pressure Die Casting

2009 ◽  
Vol 618-619 ◽  
pp. 21-26 ◽  
Author(s):  
Ambavalavanar Tharumarajah ◽  
Dayalan R. Gunasegaram ◽  
Paul Koltun
Keyword(s):  
High Pressure ◽  
Magnesium Alloy ◽  
Greenhouse Gas ◽  
Process Parameters ◽  
Die Casting ◽  
Ghg Emissions ◽  
High Pressure Die Casting ◽  
Cycle Times ◽  
Die Castings ◽  
Pressure Die Casting

In spite of die castings being amongst the highest volume items manufactured by the metalworking industry, the influence of high pressure die casting (HPDC) process parameters on greenhouse gas (GHG) emissions remains largely unreported. In this article, the authors discuss the effect of some HPDC process parameters on GHG emissions using cradle-to-gate life cycle assessment (LCA) for both aluminium and magnesium alloys. Although the impacts reduced with increasing yields in both cases, it was determined that the GHG impact of magnesium alloy HPDC was more sensitive to HPDC yield irrespective of the ratio of primary/secondary alloys in the melt charge. The reasons for this include a greater dependence of magnesium alloy HPDC on high-emitting primary processing and the use of the highly potent GHG SF6 for melting. For magnesium alloy HPDC, a decrease in quality assurance (QA) rejects and cycle times also reduced GHG emissions, although their influences were found to be an order lower than that of yield.

Estimation of Die Release Force of mboxJIS-ADC12 Aluminum Alloy Die Castings Manufactured Through High-Pressure Die Casting via Computer Simulation

2018 ◽  
Vol 12 (6) ◽  
pp. 955-963
Author(s):  
Makoto Nikawa ◽  
Kengo Usui ◽  
Hiroaki Iwahori ◽  
Atsushi Sato ◽  
Minoru Yamashita ◽  
...  
Keyword(s):  
High Pressure ◽  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Die Casting ◽  
Coupled Analysis ◽  
Fe Model ◽  
High Pressure Die Casting ◽  
Die Castings ◽  
Pressure Die Casting ◽  
Release Force

A method for the estimation of the die release force of die castings of JIS-ADC12 aluminum alloy manufactured through high-pressure die casting was examined. The die release force was evaluated by the strain in the axial direction of the extrusion pin when releasing the die castings. In this research, it was assumed that the factors that influenced the die release force were the thermal deformation of the die and die castings and the reaction layer of Al and Fe generated during the solidification process in the die. These factors in the resistance of the die release were evaluated by the friction coefficient. The die and die castings temperature in the die release process were simulated, and calculation results were mapped onto an FE model, and a coupled analysis of the thermal structure was performed. The calculated value of the mold release force was approximately the same as the actual value, and the friction coefficient was estimated to be approximately 0.5.

A Development of Virtual Manufacturing System for Magnesium High Pressure Die Casting Processes

Materials ◽  
2003 ◽  
Author(s):  
Weilong Chen
Keyword(s):  
High Pressure ◽  
Magnesium Alloys ◽  
Die Casting ◽  
Virtual Manufacturing ◽  
Mold Design ◽  
High Pressure Die Casting ◽  
Molten Magnesium ◽  
Pressure Die Casting ◽  
Soft And Hardware ◽  
Free Magnesium

In recent years, high-pressure die-casting magnesium components have been gaining currency worldwide because of the excellent properties that magnesium alloys can offer to meet new product requirements. With the increasing application of magnesium parts worldwide, many research and development projects have been carried out to advance HPDC technology. However, truly optimized mold design and production of defect free castings remains a challenge for die casters. For many HPDC magnesium products, especially those specified for porosity-free and high cosmetic requirement, the challenge not only comes form a lack of a deeper understanding of how molten magnesium alloys fill the mold cavity and form defects, but also from improper preliminary part design. This study proposes a virtual prototyping system that integrates several effective soft and hardware tools for both the part and mold-design engineer to evaluate part manufacturability. Also, investigated in this study are the major causes of those defects that are the predominant cause of rejection of thin walled, leak-free magnesium parts requiring highly cosmetic finishes.

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