Comprehensive investment casting a cleaning and casting method

Investmentcasting a clear main content is:
(1) removed from the casting mold shell;
(2) from water take system took down casting;
(3) to remove the adhesive of the casting mold shell refractory materials;
(4) casting heat treatment after cleaning, such as scale removal, all sides and cutting gate residual, etc.
Investment casting a common casting methods are:
1) thermal type gravity casting method has the following kinds. This is the most widely used a pouring forms, namely type shell from out of the roaster, at high temperature by pouring in. At this time the metal shell type cooling slowly, can be in higher liquidity under the condition of filling mold, the casting can be a very good copy the shape of the cavity, and improve the accuracy of the casting. But casting in hot type of slow cooling can make the grain bulky, this reduces the mechanical properties of castings. In pouring carbon steel casting, cooling slower casting surface also easy oxidation and decarbonization, which reduces the casting surface hardness, finish and dimensional accuracy.
2) vacuum suction casting will type shell in vacuum casting box, through the tiny pore type shell mold sucked the gas, liquid metal can better mold filling, copy the shape of the cavity, and improve the precision casting, prevent hole, the weakness of watering. The method has been applied in foreign countries.
3) pressure crystallization will type shell on pressure tank for pouring, be over after, immediately confining pressure tank, access to the tank pressure air or inert gas, make the casting solidification under pressure to increase the density of castings. In foreign maximum pressure has reached 150 ATM.
4) directional crystallization (directional solidification) some investment casting such as turbine blade, magnetic steel and so on, if their crystal structure is arranged in a certain direction of columnar crystal, their working performance can improve a lot, so investment casting directional crystallization technology is rapidly developed.