预防大型薄壁铝合金铸件裂纹的新措施——冷硬树脂砂中空型芯

A New Method for Preventing Large Thinwall Aluminum Alloy Castings From Tears-Hollow Core of Cold-setting Resin Sand

提出了采用冷硬树脂砂中空芯预防大型薄壁铝合金铸件裂纹这一新方法,给出了砂芯烧损层的概念;在实测边界条件、计算机模拟温度场的基础上,推导出砂芯烧损层厚度△δ的估算公式;分析了制芯、运输、浇注生产过程对型芯强度的要求,确定了中空芯壁厚值,通过生产验证,获得了无裂纹、表面光洁,尺寸精确的铸件。

Abstract In order to prevent large thin-wall aluminum alloy castings from tears, a now method using the hollow core of cold-setting resin sand is presented. Based, on the boundary conditions tested practically and computer simulation of temperature distribution, the conception of burn-off depth of the sand core and the formula for estimating them were derived. The requirement for strength of sand core in the process of core-making, transportation and casting was analysed, the optimal wall thickness of hollow sand core was determined. The experimental results showed that the large thin-wall Al-alloy casting with high accuracy, finished surface and no tears can be produced when using hollow cores of cold-setting resin sand.