纯铝中铸造大长径比阵列细孔孔芯抽芯力的研究

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 657-752Nat different temperatures.