二硼化铼单晶与块材的硬度

Single Crystal and Polycrystalline Bulk Hardness of Rhenium Diboride

利用高温高压的方法合成了单相ReB2块材,研究了不同载荷对ReB2单晶与多晶块体所测硬度值的影响。纳米压痕仪测得ReB2单晶的渐近线硬度值为(32.2±1)GPa;显微硬度计测得ReB2多晶块材的渐近线硬度值为(17.1±0.5)GPa,表明ReB2是一种高硬度材料,而不是一种超硬材料。另外根据材料的拉曼振动模与硬度的内在关系,估算了ReB2单晶的硬度,其计算值与实验值相吻合。

We synthesize single-phase bulk ReB2 by using method of high temperature and high pressure;and study effect of different loads on measured hardness of ReB2 single crystal and polycrystalline bulk.Nano-indentation tes-ter measures asymptotic hardness value of both ReB2 single crystal（32.2±1） GPa and polycrystalline bulk ReB2（17.1±0.5） GPa.These show that ReB2 is only a hard material,not a superhard material.In addition,according to intrinsic relationship between Raman vibration modes and hardness,we also assess that for ReB2 single crystal hardness its calculated value is consistent with experimental data.