Preparation method of sizing agent of mold core for investment casting

Abstract

The invention discloses a preparation method of a sizing agent of a mold core for investment casting. The preparation method comprises the following steps: (1) putting powder and a mineralizing agent into a ball grinder to carry out mixed grinding for more than 2 hours, taking out and drying so as to cause moisture content to be less than 0.3wt%; and (2) adding 15wt%-wt20% of plasticizer into a stainless steel container with a stirrer, heating to 85-90 DEG C, adding powder and 0.5-1.0wt% of oleic acid under the condition of stirring, and continuously stirring for 4-5 hours to obtain the sizing agent which is used for preparing the core or is cast into ingots for later use. The preparation method has the beneficial effects that a mold core green body made of quartz glass is used; after being heated to above 1100 DEG C, the mold core green body can be sintered; the mineralizing agent can facilitate sintering and has the effects of improving the high-temperature anti-deformation capacity of the mold core, increasing the crystallization rate of quartz glass and the like; and all the performances such as the porosity, bending resistance, volume density and the sintering shrinkage of the mold core are improved by using the use amount of the plasticizer.

Description

technical field [0001] The invention relates to the technical field of investment casting, in particular to a slurry preparation method for a core for investment castings. Background technique [0002] In general, the inner cavity of investment casting is formed together with the outer shape through processes such as coating and sanding, without the need for an autocratic core. However, when the inner cavity of the casting is too narrow or complex in shape, conventional processes such as coating and sanding cannot be implemented at all, or when the inner shell cannot be dried and hardened, a prefabricated core must be used to form the inner cavity of the casting. These cores should be removed after the casting is cast. For example, the hollow turbine blade of an aero-engine, the cooling channel of the blade is tortuous and labyrinthine, so a ceramic core must be used. [0003] At present, the cores used in investment casting can be divided into several types according to t...

AI Technical Summary

Problems solved by technology

[0004] However, the slurry preparation of the core for investment casting is an important factor in the quality of the core. The strength of the core in the prior art is low, and the molded core body must be heated to a high temperature for sintering to achieve high performance. , but the ceramic core is different from ordinary ceramic products, requiring a certain porosity, and the strength should not be too high

Otherwise, it will not only be difficult to remove from the casting, but also cause hot cracking of the casting