What are the causes of deformation of precision castings?

Reasons for deformation of machine tool precision castings: Prevent sudden changes in wall thickness. Machine tool precision castings with small and uniform wall thickness condense at the same time, machine tool precision castings with uneven wall thickness condense from thin to thick, and the cold iron is placed reasonably. During the casting process, it should not be shortened Casting of precision castings with internal or external irregularly shaped holes.

For dry CNC machine tools, since all processing is controlled by accounting instructions, the impact of thermal deformation is more serious. Before painting the machine tool, the bed body should be inspected for casting sound, to check for uneven surface appearance, trimming with tools, and external dirt. It should be clean. Pouring is continuous. The sticky sand on the machine tool casting surface should be covered with a layer of metal (or metal oxide) and sand (or coating) mixture or a layer of sintered sand. Therefore, the appearance of our country's machine tool precision castings is relatively rough. Reduce the gap between sand grains. Appropriately reduce the pouring temperature of metal. Improve the fire resistance of progressive sand and core sand. After the bed body precision casting is processed, clean or clean it with metal cleaning agent or cleaning industrial gasoline to ensure the appearance of oil and other dirt. .Continuous flow during pouring.

Strictly control the molding sand function and molding operation, and pay attention to cleaning the mold cavity before closing the mold. Increase the temperature of the molten iron. Reduce the slag viscosity. The slag-stopping ability of the advanced pouring system. Increase the rounded corners of precision castings of machine tools. Thermal cracks are permeable or not permeable. Through the pear lines on the machine or bed precision castings (note that it is through the curved shape), the metal and epidermal cells are oxidized. The wall thickness of the machine tool precision castings should be as uniform as possible to improve the concessions of the molding sand and core.