What are the reasons for surface pores, blisters and slag holes in the motor housing?

The motor housing has the function of protecting the motor and prolonging the service life of the motor. So we must pay attention to the design and manufacture of the motor housing to avoid some quality problems, such as surface pores, blisters, and slag holes. It is necessary to understand the causes of these problems to avoid them. Let us understand these three problems below. 1. Reasons for surface pores: (1) The amount of resin added is too large, resulting in too much gas; (2) The mold is manually baked with a blowtorch, which is difficult to achieve uniform drying; (3) The casting temperature of the molten iron is too low. Entrained gas during pouring is difficult to discharge; (4) The speed of molten iron entering the mold is too fast, causing the gas in the cavity to be too late to discharge. 2. Causes of sand holes: (1) The curing time of the sand mold is too short, and the strength of the resin sand is not enough, and local sand or broken sand occurs during the pouring process; (2) The speed of the molten iron entering the mold is too fast, which is easy to cause sand washing; (3) The operator is not careful, and the broken sand in the cavity is poured before it is cleaned. 3. Reasons for slag holes: (1) The slag is not clean before pouring of molten iron; (2) The slag retaining effect of the pouring system is not good; (3) The opening position of the inner runner is improper; (4) Floating inoculation produces secondary Scum. [Related recommendation] Learn more: Steps to disassemble the motor housing Learn more: Ten reasons for the dimensional error of the motor housing Learn more: How to improve the machining accuracy of the motor housing