立方氮化硼的热膨胀性

THERMAL EXPANSION OF CUBIC BORON NITRIDE

通过高温高压方法合成了目前制作c-BN工具的最常用的琥珀色c-BN磨料,利用超大功率高温X射线衍射仪精确测定c-BN的晶格常数,得出晶格常数随温度变化的关系,从而精确计算c-BN的本征热膨胀系数.从室温到1000℃温度范围内,c-BN的平均线膨胀系数α=4.92×10^(-6)/℃,平均体膨胀系数万β=1.47×10^(-5)/℃.

Cubic boron nitride (c-BN) was synthesized under high temperature and high pressure from the graphite-like hexagonal boron nitride (h-BN). The lattice parameters of c-BN have been measured in the temperature range from room temperature to 1000 degreesC using high power high temperature XRD under room pressure. Therefore its intrinsic thermal expansion coefficients were obtained. The average linear thermal expansion coefficient and the average bulk thermal expansion coefficient are 4.92x10(-6) / degreesC and 1.47x10(-5)/ degreesC respectively.