Study On Micro-jet Injection Technology Of Potassium Carbonate Water-soluble Core

Water-soluble cores are widely used in aluminum alloy castings with complex lumens and curved channels,because of their high efficiency water-soluble collapsibility and excellent environment-friendly properties.The traditional molding method,in the core preparation process need to use the core mold,which makes the core process complex and constraints of the development of water-soluble core.The rapid development of moldless rapid prototyping technology has been rapid in the field of casting because of its design and manufacturing integration,flexible forming process,subjectivity and diversification.Therefore,In this paper,the effects of the parameters of the molding process and the post-treatment process on the performance of the water-soluble core of potassium carbonate were systematically studied.Using the rapid prototyping method of droplet jet molding technology and potassium carbonate solution as a binder,Baozhu sand as forming powder,which wish to obtain high-strength and water-soluble core.The main contents of this paper are as follows:1)The penetration depth of different potassium carbonate solution in porous media was studied by flow-3d numerical simulation,which provided the basis for determining the thickness of the powder.The results of the study determined the thickness of the powder layer is 0.035 cm.2)The formation process parameters have important influence on the performance of the core.In this study,the single factor variable method was used to consider the Forming Parameters on Initial Strength of Potassium Carbonate Water-soluble Core,Including the concentration of potassium carbonate solution,the initial heating temperature and the additive content.The results show that the initial tensile strength of the potassium carbonate water-soluble core was increased first and then decreased with the increase of the concentration of potassium carbonate solution and the increase of the initial heating temperature.However,as the additive content increases,it decreases.3)The post-treatment process enhances the strength of the water-soluble core.In this study,the effects of infiltration solution concentration,sintering temperature andholding time before and after infiltration on the tensile strength of cores were investigated.The results show that,The initial core to which the bentonite has been added can be wetted after sintering and the strength of the obtained core is better when the concentration of the infiltrated solution is 50%;The effect of different sintering temperature on the tensile strength of the different sintering temperature is different.Not only the concentration of the binder solution has its influence on the crystal morphology,but also the sintering temperature and the holding time will affect the crystal morphology.And affect the fracture of the core and fracture morphology.After the post-treatment of water-soluble core tensile strength of up to 2MPa or more.4)The water-soluble collapsibility of the water-soluble core after forming was studied.The results show that the water-soluble core obtained by droplet injection molding and post-treatment is excellent in collapsibility.That is to say this water-soluble core can be used for pouring complex aluminum alloy castings.