耐腐蚀性能和拉伸性能提升的 α 型钛合金设计

Design of α-type Titanium Alloys with Improved Corrosion Resistance and Tensile Properties

摘要:

通过2个电子参数（结合次数Bo_t和d轨道能级Md_t）提出了新设计的α型钛（α-Ti）合金。新设计合金Ti-5Al-4Zr-3.6Sn、改性合金Ti-5Al-3Sn-1.9Zr和参考合金Ti-5Al-2.5Sn具有相同的Bo_t值（3.847）以及不同的Md_t值（2.430，2.426，2.422）。测试了3种α-Ti合金的极限抗拉伸强度（σ_UTS）、断裂应变（?_f）和热盐腐蚀性能。3种α-Ti合金均采用冷坩埚悬浮熔炼技术进行制备。结果表明，3种合金样品均具有均匀的微观结构。在3种α-Ti合金中测量到的α单相晶粒尺寸约为600 μm。Ti-5Al-4Zr-3.6Sn合金的σ_UTS和?_f值为801 MPa和16%，Ti-5Al-3Sn-1.9Zr合金的σ_UTS和?_f值为708 MPa和15%，Ti-5Al-2.5Sn合金的σ_UTS和?_f值为603 MPa和15%。热盐腐蚀测试进行28.8 ks后显示Ti-5Al-4Zr-3.6Sn、Ti-5Al-3Sn-1.9Zr和Ti-5Al-2.5Sn合金的失重率为2.61%、2.83%和3.10%。σ_UTS、?_f和耐热盐腐蚀结果表明，新设计合金Ti-5Al-4Zr-3.6Sn是一种有实际应用潜力的钛合金材料。

Abstract:

Newly designed α-type titanium (α-Ti) alloys were proposed based on both electron parameters (bonding time Bo_t and d-orbital energy level Md_t). The newly designed α-Ti alloy Ti-5Al-4Zr-3.6Sn, modified alloy Ti-5Al-3Sn-1.9Zr, and reference alloy Ti-5Al-2.5Sn have the same Bo_t value of 3.847 and different Md_t values of 2.430, 2.426, and 2.422, respectively. The ultimate tensile strength (σ_UTS), fracture strain (?_f), and hot salt corrosion resistance of the three α-Ti alloys were measured. The three α-Ti alloys were produced by the cold crucible levitation melting (CCLM) technique. Results show that homogeneous microstructures can be observed in three α-Ti alloys. The α mono-phase in three α-Ti alloys has the grain size of approximately 600 μm. σ_UTS and ?_f of Ti-5Al-4Zr-3.6Sn alloy are 801 MPa and 16%, respectively; σ_UTS and ?_f of Ti-5Al-3Sn-1.9Zr alloy are 708 MPa and 15%, respectively; σ_UTS and ?_f of Ti-5Al-2.5Sn alloy are 603 MPa and 15%, respectively. After hot salt corrosion tests were conducted for 28.8 ks, the mass loss ratio of Ti-5Al-4Zr-3.6Sn, Ti-5Al-3Sn-1.9Zr, and Ti-5Al-2.5Sn alloys is 2.61%, 2.83%, and 3.10%, respectively. The results of σ_UTS, ?_f, and hot salt corrosion resistance indicate that the newly designed alloy Ti-5Al-4Zr-3.6Sn has great potential for practical applications.