Numerical and experimental approach to eliminate defects in al alloy pump- crank case processed through gravity die casting route

S.AravindP.RagupathiG.VigneshDepartment of Mechanical Engineering, Karpagam Academy of Higher Education, Coimbatore, Tamil Nadu 641 021, India

Received 30 June 2020, Accepted 14 July 2020, Available online 14 August 2020.

Abstract

A numerical investigation was carried out with the help of computer based casting simulation software to eliminate defects such as shrinkage due to solidification, cracks, imperfect mould cavities and riser level issues. This investigation also helps to improvise the casting process done by gravity method in aluminium based alloys. The defects mentioned above are occurring in the castings due to wrong choice in selecting the process variables or gating and riser design. In this investigation, MAGMASOFT software was used for simulate the casting process undergoing solidification. The results from the simulation shows the possible areas which may be subjected to defects or any other malfunction. Before entertaining the simulation software, few castings were manufactured by making alterations in the process variables and the same castings were modeled and tested using the software. Then, using the MAGMAsoft software, simulations were carried out by modifying the position of the core pins and making possible design changes in the casting component without compromising its design intention. The simulation results showed that, the design changes helped in reducing the casting defects of the centrifugal pump crank case. Based on the simulation result, the castings were produced and checked for the defects. The casting obtained as per the modifications done based on the simulation result showed zero defects.

Korea

컴퓨터 기반 주조 시뮬레이션 소프트웨어의 도움으로 수치 조사를 수행하여 응고, 균열, 불완전한 금형 캐비티 및 라이저 레벨 문제로 인한 수축과 같은 결함을 제거했습니다. 이 조사는 또한 알루미늄 기반 합금에서 중력 방법으로 수행되는 주조 공정을 즉석에서 만드는 데 도움이 됩니다.

위에서 언급한 결함은 공정 변수 또는 게이팅 및 라이저 설계를 잘못 선택하여 주물에서 발생합니다. 이 조사에서 MAGMASOFT 소프트웨어는 응고되는 주조 공정을 시뮬레이션하는 데 사용되었습니다. 시뮬레이션 결과는 결함이나 기타 오작동이 발생할 수 있는 영역을 보여줍니다. 시뮬레이션 소프트웨어를 사용하기 전에 공정 변수를 변경하여 몇 가지 주조물을 제조했으며 동일한 주조물을 소프트웨어를 사용하여 모델링하고 테스트했습니다. 그런 다음 MAGMAsoft 소프트웨어를 사용하여 코어 핀의 위치를 ​​수정하고 설계 의도를 손상시키지 않으면 서 주조 부품에서 가능한 설계 변경을 통해 시뮬레이션을 수행했습니다. 시뮬레이션 결과는 설계 변경이 원심 펌프 크랭크 케이스의 주조 결함을 줄이는 데 도움이되는 것으로 나타났습니다. 시뮬레이션 결과를 바탕으로 주조품을 제작하고 결함을 확인했습니다. 시뮬레이션 결과를 기반으로 한 수정에 따라 얻은 주조는 결함이 전혀 없었습니다.

Fig. 1. a) Pin holes observed in the top side casting; b) Blow holes observed in tapped holes; c) Porosity is observed in top side of the casting.
Fig. 1. a) Pin holes observed in the top side casting; b) Blow holes observed in tapped holes; c) Porosity is observed in top side of the casting.
Fig. 2. (a) Deep seated shrinkage in the square end face tapped holes, (b) Shrinkage area from another angle showing damaged threads, (c) Large scale shrinkage in the thickest sections- Al cut piece.
Fig. 2. (a) Deep seated shrinkage in the square end face tapped holes, (b) Shrinkage area from another angle showing damaged threads, (c) Large scale shrinkage in the thickest sections- Al cut piece.
Shrinkage area from another angle showing damaged threads, (c) Large scale shrinkage in the thickest sections- Al cut piece.
Shrinkage area from another angle showing damaged threads, (c) Large scale shrinkage in the thickest sections- Al cut piece.

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