纯铝中铸造大长径比阵列细孔孔芯抽芯力的研究

Study on Core-Pulling Force for Array Micro-Holes with Large Aspect Ratio by Casting in Aluminium

利用涂覆石墨涂料的金属丝孔芯,成功铸出大长径比铝基阵列细孔试样。借助扫描电镜、激光共聚焦显微镜检测手段对获得的阵列细孔形貌及几何参数进行测量分析,进而揭示抽芯力及其影响因素。结果表明:孔芯与铝基体接触面上摩擦因数几乎均接近于0.25;温度与抽芯力存在线性关系,随着温度的降低,抽芯力也降低,孔芯在金属基体内部移动的距离增加;不同温度下抽芯力约在657~752 N之间。

Array micro-hole with a large aspect ratio in cast aluminium alloy was obtained by using metal wire core which was coated with graphite paint. The morphology and geometrical parameter of the micro-holes were measured and analyzed by the scanning electron microscope and laser confocal microscope, and the core-pulling force and its influence factors were studied further. The results indicate that the friction coefficient on the contact surface between the aluminium matrix and hole core is nearly close to 0.25. There is a linear relationship between the temperature and the core-pulling force. With the temperature decreasing, the core force decreases, and the distance of the hole core moving within the metal matrix increases. The core-pulling force is about 657-752 N at different temperatures.