Equivalence of ball milling and thermal treatment for phase transitions in the Al2O3 system (original) (raw)
1994, Journal of Alloys and Compounds
High energy ball milling has recently become a very popular research topic, since virtually any composition can be manufactured using a mixture of elemental (mechanical alloying) or readily available master alloy powders (mechanical grinding). Many solid state reactions, which normally occur at elevated temperatures, can be facilitated by high energy milling [1, 2]. However, a very important parameter of mechanical milling, the powder temperature during milling (called an effective local temperature or a peak temperature at the collision site) is still surrounded by controversy formation of local melts [3], well below the melting point [4], a maximum temperature rise of only 38 °C [5], an excessive heating during milling [6], of up to 407 °C [7], as high as 180 °C [8], about 280 °C [9], exceeding 570 °C [10], over 500 °C [11]). Using the well-known temperatureinduced transition sequence of aluminas, we present experimental evidence that the effective local temperature should be even higher than 700 °C.