(1. 攀鋼集團(tuán)研究院有限公司 釩鈦資源綜合利用國(guó)家重點(diǎn)實(shí)驗(yàn)室，攀枝花 617000；
2. 昆明理工大學(xué) 稀貴及有色金屬先進(jìn)材料教育部重點(diǎn)實(shí)驗(yàn)室，昆明 650093)
摘 要: 采用基于密度泛函理論(DFT)的第一性原理贗勢(shì)平面波方法，計(jì)算Ti-Ni合金系中TiNi、Ti2Ni和TiNi3金屬間化合物的平衡晶格常數(shù)、生成焓、內(nèi)聚能、力學(xué)性質(zhì)、德拜溫度和電子結(jié)構(gòu)。計(jì)算結(jié)果表明：TiNi、Ti2Ni和TiNi3金屬間化合物均具有熱力學(xué)穩(wěn)定性且容易合金化生成，合金形成能力由強(qiáng)到弱的排序?yàn)門iNi3、TiNi、Ti2Ni；3種金屬間化合物的晶體結(jié)構(gòu)在能量上和力學(xué)上都是穩(wěn)定的，結(jié)構(gòu)穩(wěn)定性由大到小排序依次為Ti2Ni、TiNi、TiNi3；TiNi和Ti2Ni為延性相(延展性Ti2Ni大于TiNi的)，TiNi3的延展性較差；3d電子是TiNi、Ti2Ni和TiNi3金屬間化合物的最主要的成鍵電子，在這3種金屬間化合物中，隨著Ni相對(duì)含量的增加，平均成鍵電子數(shù)增多，共價(jià)鍵的比例增加，化學(xué)鍵的強(qiáng)度增強(qiáng)，金屬性減弱，從而使得其彈性模量、硬度和德拜溫度均逐漸升高。
關(guān)鍵字: Ti-Ni；金屬間化合物；電子結(jié)構(gòu)；力學(xué)性質(zhì)；第一性原理
（1. Pangang Group Research Institute Co., Ltd., State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization, Panzhihua 617000, China;
2. Key Laboratory of Advance Material of Rare Precious and Nonferrous Metals, Kunming University of Science and Technology, Kunming 650093, China）
Abstract:The crystal structure, enthalpy of formation, cohesive energy, mechanical properties, Debye temperature and electronic structure of TiNi, Ti2Ni and TiNi3 intermetallic compounds were calculated by using first-principles ultrasoft pseudo-potential approach of the plane wave based on density functional theory (DFT). The calculated results show that three intermetallic compounds all have thermodynamic stability and are easy to form alloy. TiNi3 has the strongest alloys forming ability. The crystal structures of those intermetallic compounds are stable in energy and mechanics, the stability in descending order are as follows: Ti2Ni, TiNi, TiNi3. TiNi and Ti2Ni are ductile, and the ductility of Ti2Ni is significantly higher than that of TiNi. TiNi3 has a poor ductility. The 3d electronics are the mainly bonding electrons. As the increase of relative amounts of Ni in those intermetallic compounds, the average bonding electrons are growing, the strength of chemical bonds enhance, the metallicity weakens. This leads to gradually increase of the elasticity modulus, hardness and Debey temperature.
Key words: Ti-Ni; intermetallic compound; electronic structure; mechanical property; first-principle
