Introduction to the advantages and disadvantages of investment casting

Pouring can be done under gravity, or by evacuating the template first and then under low vacuum. The specific selection method depends on the casting type. Other materials that can replace paraffin as the pattern material for investment casting include plastics and the like. Investment casting has the following advantages. (1) Castings with complex shapes that are difficult to form by other casting methods can be produced. (2) There is no parting surface, so there will be no wrong box. (3) Under appropriate conditions, the grain size, grain orientation and solidification direction can be controlled by investment casting method to obtain the desired mechanical properties. (4) The molding sand on the surface of the inner cavity of the precision casting shell is very fine, so the precision casting has a high tolerance level and a good surface quality. (5) Precision castings can be processed without surface processing, or only a small amount of processing, especially suitable for difficult-to-machine materials such as nickel-chromium alloys. The disadvantages of investment casting are as follows. (1) Since the wax mold making and template making process involve a lot of manual operations, the production cost is high. (2) Generally, there are certain restrictions on the size and weight of castings. The upper limit of casting weight is generally around 5 kg. In ancient times, precision casting was mainly used to manufacture works of art, jewelry and jade accessories and surgical instruments. Modern precision casting products include gas turbine impellers and blades, weaving machines, movie camera pawls and handles, radar waveguides, stainless steel valve bodies and turbocharger impellers.