(合肥工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院, 合肥, 230009)
摘 要: 真空熔結(jié)NiCrBSi合金涂層中主要的強(qiáng)化相CrB對(duì)合金涂層宏觀性能的影響很大。 采用分子經(jīng)驗(yàn)電子理論（EET）計(jì)算了CrB相的價(jià)電子結(jié)構(gòu)。 結(jié)果表明： CrB結(jié)構(gòu)中最強(qiáng)鍵是同一（100）面上的兩個(gè)B原子組成的鍵； 相鄰（100）面上的兩對(duì)Cr—B原子對(duì)組成的結(jié)合鍵次之；多組次強(qiáng)鍵分布于滑移面之間， 且等同鍵數(shù)多、 鍵絡(luò)分布均勻、 主干鍵絡(luò)鍵能高； （100）面上強(qiáng)鍵等同鍵數(shù)少、分布不對(duì)稱, 弱鍵很弱， 在應(yīng)力作用下易因弱鍵斷開(kāi)而產(chǎn)生微裂紋， 因此CrB具有高硬度、高熔點(diǎn)和高脆性。
關(guān)鍵字: 價(jià)電子； 鎳基合金； 硬度； 熔點(diǎn)； 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
