Vacuum assisted high pressure die casting of aluminium alloys

Niu, X.P.; Hu, B.H.; Pinwill, I.; Li, Haisu

doi:10.1016/s0924-0136(00)00545-8

Cited by 160 publications

(68 citation statements)

References 2 publications

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“…During the heat treatment, the morphology of the eutectic Si is modified from needle shaped to a more spherical geometries 11 . In addition, the spheroidized Si particles and refined precipitates can provide a retard in cracks nucleation, resulting in a much-improved casting ductility 12 . Semi-rapid solidification rates may be adequate to induce microstructural changes such as refinement of phases, including the Fe-Si intermetallic compounds, increasing the solubility of some elements in the matrix, modification of acicular eutectic silicon and suppress the formation of detrimental precipitates [13][14][15] .…”

Section: Introductionmentioning

confidence: 99%

Study of the Al-Si-X system by different cooling rates and heat treatment

et al. 2012

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The solidification behavior of the Al-12.6% Si (A1), the hypereutectic Al-20%Si (A2) and the Al-20%Si-1.5% Fe-0.5%Mn (A3) (in wt. (%)) alloys, at different cooling rates is reported and discussed. The cooling rates ranged between 0.93 °C/s and 190 °C/s when cast in sand and copper wedge-shaped molds, respectively. A spheroidization heat treatment was carried out to the alloys in the as-cast condition at 540 °C for 11 hours and quench in water with a subsequent heat treatment at 170 °C for 5 hours with the purpose of improving the mechanical properties. The samples were characterized by optical microscopy, scanning electron microscopy and mechanically by tensile test, in order to evaluate the response of the heat treatment on the different starting microstructures and mechanical properties. It was found that alloys cooled at rates greater than 10.8 °C/s had a smaller particle size and better distribution, also showed a greater response to spheroidization heat treatment of all silicon (Si) phases. The spheroidization heat treatment caused an increase in the ultimate tensile stress (UTS) and elongation when compared with the alloys in the as-cast condition. The highest UTS value of 174 MPa was obtained for the (A1) alloy.

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Section: Introductionmentioning

confidence: 99%

Study of the Al-Si-X system by different cooling rates and heat treatment

et al. 2012

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“…그러나 기존의 다이캐스팅 공정 시 캐비티 내부에 형성되는 주조 결함은 내구재와 같은 고강도가 요구되는 부품에 대한 적용을 제한했으며, 이러한 내부 결함 은 대부분은 사출시 혼입되는 공기에 의해 다이캐스팅 주물 내 10~40cc / 100gAl의 많은 가스기포결함을 형성한다 [3][4][5]. 다이캐스팅 공정 시 금형에 갇힌 가스는 용탕이 충전되고 응고된 후에 기포결함의 원인이 되며, 캐비티 및 슬리브 내 에서 충전되는 동안 공기가 혼입되기 쉬우므로 이를 최소화 시킬 필요가 있다 [6,7]. 다이캐스팅 공정에서 공기 혼입을 최 소화하기 위한 방편의 하나로 플런저를 두 단계(저속구간, 고 속구간)로 이동시키는 방법이 적용되고 있다.…”

Section: 서 론unclassified

Effect of Casting Thickness and Plunger Velocity on Porosity in Al Plate Diecasting

Kang¹,

Park²,

Kim³

et al. 2015

Journal of Korea Foundry Society

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The Al die casting process has been widely used in the manufacturing of automotive parts when the process requires near-net shape casting and a high productive rate. However, porosity arises in the casting process, and this hampers the wider use of this method for the creation of high-durability automotive components. The porosity can be controlled by the shot condition, but, it is critical to set the shot condition in the sleeve, and it remains difficult to optimize the shot condition to avoid air entrapment efficiently. In this study, the 4.5 mm, 2.0 mm plate die castings were fabricated under various shot conditions, such as plunger velocities of 0.7 m/s~3.0 m/s and fast shot set points of the cavity of −25%, 0%, 25%, and 50%. The mold filling behavior of Al melts in the cavity was analyzed by a numerical method. Also, according to the shot conditions, the results of numerical analyses were compared to those of die-casting experiments. The porosity levels of the plate castings were analyzed by X-ray CT images and by density and microstructural analyses. The effects of the porosity on the mechanical properties were analyzed by tensile tests and hardness tests. The simulation results are in good general agreements with the die-casting experimental results. When plunger velocity and fast shot set point are 1.0 m/s and cavity 25% position, castings had optimum condition for good mechanical properties and a low level of porosity.

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“…특히, 진공 다이캐스팅은 일반 다이캐스팅에서 발 생하는 가스 포집에 의한 기공, 미충전 등을 억제하여 고 신뢰 성이 요구되는 부품을 생산할 수 있다 [4]. 다이캐스팅 공정은 이러한 장점이 있음에도 불구하고, 1 mm 이하의 박육(Thin walled) 제품을 제조하기란 상당히 어렵기 때문에 분리판을 주 조공법으로 제작하는 연구는 미비하다.…”

Section: 서 론unclassified

Fabrication Process of Aluminum Bipolar Plate for Fuel Cell using Vacuum Die Casting

Jin¹,

Kang²

2011

Journal of the Korea Foundry Society

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This study aims to investigate the formability of bipolar plates for fuel cell fabricated by vacuum die casting of ALDC 6. Cavity shape of mold is thin walled plate (size: 200 mm × 200 mm × 0.8 mm) with a serpentine channel (active area: 50 mm × 50 mm). Before bipolar plate was made by HPDC, computational filling behavior and solidification was performed by MAGMA soft. The final mold design for location and direction of channel was determined by computational simulation. Also, according to injection speed conditions, simulation result was compared to actual die casting experimental result. When vacuum pressure, injection speed of low and high region is 350 mbar, 0.3 m/s and 2.5 m/s respectively, products had few casting defects. On the other hand, at the same as injection speed, without vacuum pressure, products had many casting defects between end of the channel and overflow.

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Vacuum assisted high pressure die casting of aluminium alloys

Cited by 160 publications

References 2 publications

Study of the Al-Si-X system by different cooling rates and heat treatment

Study of the Al-Si-X system by different cooling rates and heat treatment

Effect of Casting Thickness and Plunger Velocity on Porosity in Al Plate Diecasting

Fabrication Process of Aluminum Bipolar Plate for Fuel Cell using Vacuum Die Casting

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