(1. 大連理工大學(xué) 三束材料改性教育部重點(diǎn)實(shí)驗(yàn)室，大連 116024；
2. 大連冰山金屬技術(shù)有限公司，大連 116024；
3. 大連理工大學(xué) 能源動(dòng)力學(xué)院，大連 116024)
摘 要: 依據(jù)BCC結(jié)構(gòu)中的“團(tuán)簇加連接原子”模型確定Ti-Mo二元團(tuán)簇式[MoTi14]Mo1為基礎(chǔ)成分式，根據(jù)合金化組元Sn、Zr和Nb與基體Ti的混合焓實(shí)現(xiàn)其在基礎(chǔ)成分式中的組元替換，從而形成多元成分式[(Mo,Sn)(Ti,Zr)14]Nb1。利用銅模吸鑄快冷技術(shù)制備d 6 mm合金棒狀樣品，并對其進(jìn)行950 ℃保溫2 h并水淬。組織結(jié)構(gòu)分析和拉伸力學(xué)性能結(jié)果表明：低模量Sn、Zr和Nb分別取代基礎(chǔ)成分式中高模量的Mo時(shí)形成的三元BCC β-Ti合金結(jié)構(gòu)穩(wěn)定，且具有較低的彈性模量；當(dāng)Mo0.5Sn0.5占據(jù)團(tuán)簇心部，Nb作為連接原子，Zr替代部分Ti時(shí)形成的低Nb含量的β-Ti合金[(Mo0.5Sn0.5)(Ti13Zr)]Nb1 (Ti68.10Mo5.25Sn6.50Zr9.98Nb10.17，質(zhì)量分?jǐn)?shù)，%)具有最低的彈性模量(為43 GPa)，且斷裂強(qiáng)度σb為569 MPa，應(yīng)變?chǔ)艦?.6%。
關(guān)鍵字: Ti-Mo-Nb-Zr-Sn合金；β-Ti固溶體；成分設(shè)計(jì)；低彈性模量
（1. Key Laboratory of Materials Modification, Ministry of Education,
Dalian University of Technology, Dalian 116024, China;
2. Dalian Bingshan Metal Technology Co., Ltd., Dalian 116024, China;
3. College of Energy Source and Power, Dalian University of Technology, Dalian 116024, China）
Abstract:The basic formula of cluster formula [MoTi14]Mo1 in Ti-Mo binary alloys was determined using the cluster- plus-glue-atom-model, then a general cluster formula [(Mo,Sn)(Ti,Zr)14]Nb1 was finally formed according to the mixing enthalpies between alloying elements Sn, Zr, Nb and the matrix Ti. The designed alloys were prepared into d 6 mm rods by copper mould suction cast method, and then solution-treated at 950 ℃ for 2 h followed by water-quenching. The structures of alloys were characterized, and the tensile mechanical properties were measured. The experimental results show that the ternary alloys by Sn, Zr and Nb substituting for Mo in cluster center or shell exhibit a BCC β-Ti structure and have lower elastic modulus. A multi-component alloy with the lowest elastic modulus as well as low Nb content is gained at the composition of [(Mo0.5Sn0.5)(Ti13Zr)]Nb1 (Ti68.1Mo5.2Sn6.5Nb10.2Zr10.0, mass fraction, %), where a combination of Mo and Sn forms the cluster center Mo0.5Sn0.5, Nb serves as the glue atom, and partial Zr substitutes for Ti in the cluster shell. Its characteristic mechanical parameters are elastic modulus E of 43 GPa, tensile strength σb of 569 MPa and strain ε of 5.6%, respectively.
Key words: Ti-Mo-Nb-Zr-Sn alloys; β-Ti solid solutions; composition design; low elastic modulus
