金属型离心微铸造技术与工艺研究

Study on technology and process of centrifugal micro casting based on permanent mold

文中探讨了金属型离心微铸造技术,并针对工艺参数对微尺度件成形规律进行深入研究。依据金属型离心微铸造技术,在离心转速3000r/min,模具预热温度270℃条件下,制备出长4 mm的微尺度件,最小截面尺寸为40μm×300μm。同时得出,在微尺度条件下,铸型预热温度一定时,随着离心转速的增加,液态金属在金属型中充填长度增加,晶粒越来越细小,硬度逐渐增大,而在离心转速达到临界值后,充填长度反而下降。离心转速一定时,随着预热温度的增加,晶粒越来越粗大,同时硬度越来越低。

The centrifugal microcasting based on permanent mold is presented. The influences of the microcasting parameters on forming regularity of microscale parts produced by mierocasting are investigated. On the basis of the technology, the microscale specimens with a nominal length of 4mm and a smallest cross section of 40 μm× 300 μm are prepared under the condition of the rotational speed 3000r/ min and the temperature 270 ℃. Additionally, it is found that, in the micro scale conditions, liquid metal filling length in permanent mold increases with the increase of centrifugal speed under constant preheating temperature. Then constantly increasing centrifugal speed leads to finer grain size and higher hardness. When the centrifugal speed reaches a certain value, the filling length decreases. At the same time, larger grain and lower hardness are found with the increasing of preheating temperature under constant preheating temperature.