Al-Mg-Si-(Cu) 6xxx Series Alloy Selection for Rheo-High Pressure Die Casting

2014 ◽  
Vol 1019 ◽  
pp. 61-66
Author(s):  
Heinrich Möller ◽  
Pfarelo Daswa ◽  
Gonasagren Govender
Keyword(s):  
High Pressure ◽  
Selection Process ◽  
Die Casting ◽  
Solution Treatment ◽  
Hot Tearing ◽  
Incipient Melting ◽  
Negative Effects ◽  
High Pressure Die Casting ◽  
Pressure Die Casting ◽  
6Xxx Series

<span><span style="font-family: Times New Roman;" face="Times New Roman"><span style="font-family: Times New Roman;" face="Times New Roman"></span></span> <p><span style="font-family: Times New Roman;" face="Times New Roman">This paper investigates the selection process of Al-Mg-Si-(Cu) 6xxx series alloys when used specifically for rheo-high pressure die casting (R-HPDC). The 6xxx series alloys have been developed as wrought alloys and certain factors must be taken into consideration when utilising them for semi-solid metal processing. It is shown that chemical composition has a significant effect on the solution treatment parameters that should be employed i.e. high Cu and excess Si levels necessitate the use of a two-step solution treatment to reduce incipient melting. This incipient melting is especially severe in areas within the component where liquid segregation occurs, which is a common phenomenon in R-HPDC. However, high Cu and excess Si levels also have advantages: it results in higher T6 strength and Cu-additions have been shown to minimise the negative effects of natural pre-ageing. Therefore, the composition of the alloy must be selected in such a way as to achieve acceptable strength without the dangers of incipient melting in liquid segregated areas. Another important modification of 6xxx series alloys used for R-HPDC that is presented is the addition of Ti to minimise hot tearing. </span></p> <p align="LEFT"><span style="font-family: Times New Roman; font-size: medium;" face="Times New Roman" size="3"> </span></p>

Rheocasting of Al-Cu Alloy A201 with Different Silver Contents

2008 ◽  
Vol 141-143 ◽  
pp. 151-156 ◽  
Author(s):  
E.P. Masuku ◽  
Gonasagren Govender ◽  
L. Ivanchev ◽  
Heinrich Möller
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Grain Boundaries ◽  
Die Casting ◽  
Solution Treatment ◽  
Cast Material ◽  
High Pressure Die Casting ◽  
Cu Alloy ◽  
Pressure Die Casting ◽  
Better Than

Rheocasting of alloys A206 and A201 was investigated in this study. Conical bars with different silver contents were produced using CSIR rheoprocess technology, together with high pressure die casting. The results showed that addition of Ag to alloy A206 increased the mechanical properties of the alloy. However, the addition of Ag also resulted in Cu-rich phases to precipitate at the grain boundaries of the as-cast material. The solution treatment used in this study was unable to dissolve all of this phase, especially in the 1.12%Ag-containing alloy. This resulted in slightly decreased mechanical properties compared to the 0.63%Ag-containing alloy. The T6 mechanical properties (strength and elongation) obtained in this study for rheocast A206 and A201 are better than those reported for permanent mould castings of alloy A206 and A201.

Rheocasting an Engine Mounting Bracket in Commercial 7075

2011 ◽  
Vol 690 ◽  
pp. 133-136 ◽  
Author(s):  
Ulyate Andries Curle
Keyword(s):  
High Pressure ◽  
Die Casting ◽  
Hot Tearing ◽  
Injection Velocity ◽  
The Novel ◽  
X Ray ◽  
High Pressure Die Casting ◽  
Casting Technique ◽  
Casting Section ◽  
Pressure Die Casting

Wrought aluminium alloys are prone to hot tearing when cast into near-net shapes. This problem can be overcome by the novel casting technique of rheo-processing combined with high pressure die casting. An industrial engine mounting bracket is produced by rheo-process commercial 7075 with the patented CSIR-RCS and subsequent high pressure die casting. Section thickness changes and constraining geometry make this a difficult component to rheocast. X-ray radiography is used to evaluate hot tearing over the component and is correlated to piston injection shot profile velocities. Gross hot tearing is significantly reduced by a higher injection velocity but turbulent flow entraps air. Faster injection allows more time for flow before final solidification.

Applications of Squeeze Casting for Automobile Parts

2013 ◽  
Vol 773-774 ◽  
pp. 887-893
Author(s):  
Pongsak Dulyapraphant ◽  
Ekkachai Kittikhewtraweeserd ◽  
Nipon Denmud ◽  
Prarop Kritboonyarit ◽  
Surasak Suranuntchai
Keyword(s):  
High Pressure ◽  
Squeeze Casting ◽  
Die Casting ◽  
Solution Treatment ◽  
Casting Process ◽  
High Pressure Die Casting ◽  
Heat Treated ◽  
Automotive Parts ◽  
Die Casting Process ◽  
Pressure Die Casting

With an increasing pressure on automotive weight reduction, the demand on the lighter weight automotive components continues to increase. In recent years, squeeze casting processes have been used with different aluminium alloys to produce high integrity automotive parts. In this study, the indirect squeeze casting processes is adopted to cast a motorcycles component originally produced by a high pressure die casting process using aluminium alloy ADC12. To minimize amount of gas porosity inside squeeze casts, concepts of (1) minimization of ingate velocity along with (2) bottom filling pattern during the die filling, and (3) maximization of intensifications casting pressure are applied. Then parts are casted with both conventional high pressure die casting and indirect squeeze casting processes. Comparative evaluation of mechanical properties was made between HPDC casts and squeeze casts both in as-cast and heat treated conditions. Results from the experiment have shown that squeeze casts can pass the blister test at 490 °C for 2.5 hours. Then, squeeze casts are heat treated by solution treatment at 484 °C for 20 minutes and artificial age at 190 °C for 2.5 hours, respectively. This improves UTS of the heat treated squeeze cast to 254.14 MPa with 1.84% of elongation, while the UTS of as cast condition from both processes is not significantly different.

Fusion Welding of Rheocast Semi-Solid Metal (SSM) Processed Aluminium Alloy 7017

2012 ◽  
Vol 192-193 ◽  
pp. 161-166 ◽  
Author(s):  
Madeleine du Toit ◽  
Patronica Letsoalo ◽  
Heinrich Möller
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Aluminium Alloy ◽  
Die Casting ◽  
Solid Metal ◽  
Hot Tearing ◽  
High Pressure Die Casting ◽  
Near Net Shape ◽  
Semi Solid ◽  
Pressure Die Casting

Near-net shape casting of wrought aluminium alloys has proven to be difficult due to a tendency towards hot tearing during cooling. Rheocasting, or semi-solid metal (SSM) processing followed by high pressure die casting (HPDC), has recently been shown to be an effective alternative to conventional die casting, yielding near-net shape wrought aluminium alloy castings with less risk of hot tearing. This casting process involves pouring the liquid metal into a processing cup, which is then transferred into a coil for induction stirring and simultaneous forced air cooling. When the metal reaches the semi-solid casting temperature, the resultant slurry is transferred to a high pressure die casting machine and cast to near-net shape. This modifies the as-cast microstructure, yielding a more globular primary phase and results in mechanical properties in the -T6 condition closely approaching those of wrought material in the same condition. Little information is currently available on the response of SSM-HPDC material to welding. This project investigated the influence of autogenous laser and gas tungsten arc welding on the microstructure and mechanical properties of aluminium 7017 after rheocasting. It is possible to successfully weld this material without solidification or liquation cracking. The effect of welding on the rheocast microstructure in the heat-affected zone and weld metal was shown, and the hardness and tensile properties of the resulting joints in the as-welded condition were tested and related to the microstructures achieved.

The Heat Treatment of Rheo-High Pressure Die Cast Al-Cu-Mg-Ag Alloy 2139

2012 ◽  
Vol 192-193 ◽  
pp. 173-178 ◽  
Author(s):  
Heinrich Möller ◽  
Gonasagren Govender
Keyword(s):  
High Pressure ◽  
Tensile Properties ◽  
Artificial Aging ◽  
Die Casting ◽  
Solution Treatment ◽  
High Strength ◽  
Incipient Melting ◽  
Scanning Calorimetry ◽  
Die Cast ◽  
Pressure Die Casting

High strength wrought Al-Cu-Mg-Ag alloy 2139 was successfully processed using the CSIR rheocasting system and cast into plates using high pressure die casting. Differential scanning calorimetry was used to determine suitable homogenization/solution treatment temperatures. A two-step homogenization/solution treatment of 490oC for 24 h, followed by 520oC for 2 h does not cause any incipient melting. Artificial aging of the R-HPDC 2139 plates at 160oC for 24 h results in tensile properties similar to those reported for thixoformed casting alloy 201-T6. The minimum military specifications for wrought 2139-T8 are exceeded in terms of strength, with slightly lower ductility being obtained. Artificial aging at 153oC for 20 h results in tensile properties that exceed all the minimum military specifications for wrought 2139-T8.

Fatigue Resistance of Heat Treated Aluminium High Pressure Die-Castings

2008 ◽  
Vol 41-42 ◽  
pp. 99-104 ◽  
Author(s):  
Roger N. Lumley ◽  
J.R. Griffiths
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Fatigue Strength ◽  
Die Casting ◽  
Solution Treatment ◽  
Cyclic Stress ◽  
Fatigue Properties ◽  
High Pressure Die Casting ◽  
Heat Treated ◽  
Pressure Die Casting

High pressure die-casting (HPDC) is widely used as a cost-effective way to massproduce metal components that are required to have close dimensional tolerances and smooth surface finishes. Approximately 50%, by mass, of the aluminium castings produced worldwide are made by this manufacturing route. However, HPDC components are relatively porous compared with other types of castings and so cannot usually be conventionally heat treated to improve mechanical properties. This follows because during solution treatment (e.g. at 540°C for 8h), the pores expand, resulting in unacceptable surface blisters, distortion and poor mechanical properties. Recent work within the CSIRO Light Metals Flagship has revealed a heat treatment procedure by which the problems of blistering and distortion can be avoided [1]. As a result, large improvements in strength have been achieved, as compared with the as-cast condition. One uncertainty is the behaviour of heat treated HPDCs under cyclic stress and this paper investigates the fatigue properties of a common high pressure die-casting alloy, A380 (Al-8.5Si-3.5Cu). Comparisons are made between as-cast, T4 and T6 conditions. Fatigue strength is highest for the alloy aged to a T6 temper and ratios of fatigue strength to tensile strength for the as-cast, T4 and T6 conditions are constant at a value of approximately 0.6, which is particularly high for aluminium alloys.

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.

scholarly journals On the Use of Conformal Cooling in High-Pressure Die-Casting and Semisolid Casting

Technologies ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 39
Author(s):  
Anders E. W. Jarfors ◽  
Ruslan Sevastopol ◽  
Karamchedu Seshendra ◽  
Qing Zhang ◽  
Jacob Steggo ◽  
...  
Keyword(s):  
High Pressure ◽  
Die Casting ◽  
Life Extension ◽  
Conformal Cooling ◽  
High Pressure Die Casting ◽  
Cooling Channels ◽  
Die Life ◽  
Die Materials ◽  
Pressure Die Casting ◽  
Semisolid Casting

Today, tool life in high pressure die casting (HPDC) is of growing interest. A common agreement is that die life is primarily decided by the thermal load and temperature gradients in the die materials. Conformal cooling with the growth of additive manufacturing has raised interest as a means of extending die life. In the current paper, conformal cooling channels’ performance and effect on the thermal cycle in high-pressure die casting and rheocasting are investigated for conventional HPDC and semisolid processing. It was found that conformal cooling aids die temperature reduction, and the use of die spray may be reduced and support the die-life extension. For the die filling, the increased temperature was possibly counterproductive. Instead, it was found that the main focus for conformal cooling should be focused to manage temperature around the in-let bushing and possibly the runner system. Due to the possible higher inlet pressures for semisolid casting, particular benefits could be seen.

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