精密铸造可溶性石膏芯的研究

Study on Soluble Gypsum Core for Investment Casting

实验研究了以石膏和莫来砂为基体、以硫酸镁和P盐为添加剂的可溶性型芯性能,并考虑不同焙烧温度对其性能的影响。实验结果表明:硫酸镁能显著提高型芯的室温抗弯强度,且其加入量直接影响了型芯的溶解性,P盐的加入能使石膏混合料在高温时发生较好的烧结,并有助于室温干强度的提高,焙烧温度对型芯的强度影响显著,而加水量和试样浇注时间对表面质量影响明显。

The properties of soluble cores are s tudied by experiment in which CaSO4H2O and mSiOnAlO act as matrix and MgSO4·7H2O and P salt act as additives.Bending strength of core increases dramatic ally by adding MgSO4·7H2O at room temperature,while the solu bility of gypsum core is directly aff ected by its addition.P salt is added to make gypsum mixture get better sintering effect and higher ben ding strength at room temperature.Bending strength of core is also dram atically affected by roasting temperature.The quality of surface is obviously affected by the volume of water and th e time of pouring sample.