Production of CNC machine tool castings

Nov. 20, 2021

Castings are mainly used as blanks for machine parts, and some precision castings can also be used directly as machine parts. Casting occupies a large proportion of mechanical products. For example, in tractors, the weight of castings accounts for about 50-70% of the weight of the whole machine, 40-70% in agricultural machinery, and 70-90% in machine tools and internal combustion engines. Among all kinds of castings, mechanical castings have the largest variety, the most complex shapes, and the largest amount, accounting for about 60% of the total casting output. Followed by ingot molds for metallurgy and pipelines for engineering.

 

   The quality of non-machined surface and appearance of castings has a considerable influence on the commercial properties of castings. They include:

 

   (1) Surface unevenness (box expansion, shrinkage and sand inclusion);

 

   (2) Surface or inner cavity cleanliness (sticky sand, sticky "paint layer");

 

   (3) Flatness deviation (unworked surface undulations);

 

   (4) Surface roughness;

   (5) Contour definition (contour definition of structural units such as bosses and umbilicus, evaluated with the naked eye).