(合肥工业大学 材料科学与工程学院, 合肥, 230009)
摘 要: 真空熔结NiCrBSi合金涂层中主要的强化相CrB对合金涂层宏观性能的影响很大。 采用分子经验电子理论（EET）计算了CrB相的价电子结构。 结果表明： CrB结构中最强键是同一（100）面上的两个B原子组成的键； 相邻（100）面上的两对Cr—B原子对组成的结合键次之；多组次强键分布于滑移面之间， 且等同键数多、 键络分布均匀、 主干键络键能高； （100）面上强键等同键数少、分布不对称, 弱键很弱， 在应力作用下易因弱键断开而产生微裂纹， 因此CrB具有高硬度、高熔点和高脆性。
关键字: 价电子； 镍基合金； 硬度； 熔点； 脆性
property of CrB
（ School of Materials Science and Engineering,
Hefei University of Technology， Hefei 230009, China）
Abstract: CrB is one of the harden phase in vacuum melting NiCrBSi alloy, which has great influence on macro-properties of alloy coating. The valence electron structure of CrB phase were calculated on the base of experimental electron theory in solid and molecules （EET）. The results show that the bond between two B atoms on the same (100) plane is the strongest one, and the two bonds between two pairs of Cr—B atoms on different (100) planes are relatively weaker. There are several bonds, which are only weaker than the strongest one, existing between slip place with many equated bonds and uniformly distribution. And the main bond energy is high. The strong bonds on the (100) plane have less equated bonds and dissymmetric distribution. So, CrB phase has high hardness, high melting point and high brittleness.
Key words: valence electron; nickel base alloy; hardness; melting point; brittleness
