铝合金铸件

categories of news

Product Categories

contact us

Company Address: Tiexi Industrial Park, Haicheng City, Liaoning Province

Contact person: Manager Zhang

Contact :13112347171

mailbox:lnthjc@126.com

Company website:en.lnthjc.com




Cause analysis of collapse in Lost Foam Casting

Your current location: First page >> News >> Industry news

Cause analysis of collapse in Lost Foam Casting

Release date:2018-10-31 Author: Click:

In lost foam casting of aluminium alloy castings, box collapse is a kind of common defects in lost foam casting. The defects often occur in the production of large castings (large platform castings are more prominent) or closed or semi-closed castings. From the point of view of the whole lost foam casting process, the defects usually occur in the casting or solidification links.

The collapse defect of lost foam casting is sometimes called collapse defect or collapse of casting. With the maturity of the application of lost foam casting technology, there have been relatively detailed research results on the causes and prevention methods of collapse defect. The research results confirm that the causes of collapse defect are not unilateral. The following summaries are made on the causes of collapse defect:

A. In the process of pouring, the amount of gas produced by the decomposition of the lost foam pattern is too much and urgent, the exhaust speed of the casting can not catch up, and the insufficient suction of the vacuum pump can easily lead to the collapse and collapse of the casting pattern.

B. The "flash" of liquid metal is one of the reasons for the collapse defect. The so-called "flash" of liquid metal is that part of the liquid metal that has flowed into the position of filling the lost pattern is changed to other parts under the circumstance of external action, so that the original displaced position is occupied by no liquid metal or metal filling. This kind of problem mostly occurs in the case of top injection, large plane and one-type multi-pattern of castings.

C. If the buoyancy of molten metal is too large, the sand on the upper part of the casting mould will be easily deformed, which may lead to local collapse. Generally, the sand consumption on the top of the casting mould is small, and the negative pressure is not enough, which may cause the casting to be poorly formed or even unable to form.

D. The fire resistance and high temperature strength of the coating are not enough, so it is very easy to cause the collapse of lost foam casting. The lost foam pattern can buffer the filling and cooling of liquid metal in the casting process, and reduce the erosion of liquid metal in the casting process. When liquid metal replaces the lost foam pattern and fills the cavity, dry sand mainly relies on coating support. When the coating strength is insufficient or the refractory is insufficient, the local casting will collapse and collapse, especially over the inner runner of large castings.

Above all, the causes of collapse defects of EPC castings are various. Enterprises in production can refer to the above reasons and analyze the real causes of collapse defects of EPC castings combined with their own relevant operations, and make timely adjustments.


汽车零件销售

This article URL:http://en.lnthjc.com/news/407.html

Key words:Quotationofautomobileparts,AutoPartsProcessing,SalesofAutomotiveParts

Recently Viewed:

Liaoning Tianhai Tiancheng Equipment Manufacturing Co., Ltd. Copyright Ownership Yingkou Zhongchuang Network Technology Co., Ltd. Provides technical support