Study on Dimension Precision Control of Wax Pattern Using Water Soluble Wax Core in Investment Casting

Author of the article:SUN Bing, CHANG Huaqiang, DONG Zhenjiang, LI Shuai, QIAO Haibin, WANG Zhe, LI Bobo

Author's Workplace：LuoYang Shuang Rui Precision Casting Titanium Co., Ltd.,

Key Words： water-soluble core; compound wax pattern; dimensional accuracy; contraction

Abstract：The shrinkage law of water-soluble core and wax mold under different size and different shrinkage state in the
process of compound wax making with water-soluble core and wax mold was studied. A zigzag step model was designed
and used to carry out the compound wax making process experiment of water-soluble core and medium-temperature wax
outer mold. The influence of water-soluble core pressing wax on the free shrinkage size and limited shrinkage size of wax
outer mold was analyzed. The results show that when the base size of wax mold is 5~40 mm, the linear shrinkage of the
contact part between wax mold and water-soluble core is 0.34%~0.77%, which is about 50% lower than that of free
shrinkage. With the increase of foundation size, the amount of constricted line shrinkage increases and the shrinkage rate
decreases gradually. At the same time, in the cooling stage, the water-soluble core prevents the wax mold from concave
deformation, which better ensures the size and surface quality of the wax mold. The size fluctuation of the inner cavity of
the wax mold is controlled within 0.1 mm, which is 70% higher than that of the traditional process. The surface quality of
the wax mold is greatly improved.