Causes of foaming on metal casting surface of precision casting factory

Published on:

2020-11-06

Precision casting is divided into investment casting, ceramic mold casting, metal mold casting, pressure casting, lost foam casting, etc. if the casting is not handled properly, there may be blistering and other defects. The following precision casting manufacturer will tell you about the causes of foaming on the surface of metal casting.

First of all, let's first understand the characteristics of foaming on the surface of metal casting. It is roughly that there are protuberant bubbles on the surface of the die casting parts, which are found after die casting, exposed after polishing or machining, and appeared after oil spraying or electroplating. It is mainly the stomata and shrinkage mechanism. The stomata are often round, and the shrinkage is mostly irregular.

Causes of foaming on metal casting surface of precision casting factory

1、 The causes of blowholes are as follows: 1. The gas content of alloy liquid is too high and precipitates during solidification. When the gas in the mold cavity, the gas emitted from the coating and the gas precipitated from the alloy solidification are poor in the exhaust of the mold, the blowholes are formed in the precision casting. 2. In the process of filling and solidification of molten metal, due to the invasion of gas, the surface or interior of the casting will produce holes. 3. The gas volatilized from the paint invades.

2、 Because of the shrinkage of the metal during solidification. 2. The uneven thickness of the casting or the local overheating of the casting results in the slow solidification of a certain part, and the concave position is formed on the surface when the volume shrinks. Due to the existence of blowholes and shrinkage cavities, water may enter into the holes during surface treatment of die castings. When baking after painting and electroplating, the gas in the holes will expand due to heat; or the water in the holes will change into steam and expand in volume, resulting in foaming on the surface of castings.

Precision casting refers to the process of obtaining precise size castings. Compared with the traditional sand casting process, the size of the castings obtained by precision casting is more accurate and the surface finish is better. Yantai Ruifeng metal is a professional precision casting manufacturer. The company can develop, design and produce various precision casting parts according to customer requirements.