【摘要】 Ti-1300合金是一种亚稳β钛合金,为了从组织形貌方面解释其高强高韧的特性,对此钛合金的相变特征进行了研究。研究结果表明,由于α相的球化,此钛合金抗拉强度可达1400MPa以上,同时发现特定的板条状α相有利于保持此钛合金较高的断裂韧性(KQ≥81MPa·m1/2),与针状二次α相相比,板条状二次α相应力集中程度较轻,因此有利于获得较高的韧性。对时效过程中α相的形貌变化进行了研究,并从热力学和动力学上进行了描述,同时给出了一种比较合理的热处理制度。更多还原

【Abstract】 This article studies the phase transformation of the metastable β-Ti-Al-Mo-V-Cr-Zr alloy(Ti-1300) to disclose the morphological reason for its high strength and high fracture toughness.It has been found that its ultrahigh strength(ultimate tensile strength exceeds 1400 MPa) owes mainly to the spheroidization of the α-phase,while the high fracture toughness(exceeds 81 MPa·m1/2) to the special lath-shaped α-particles.Compared to the needle-shaped second α-articles,the coarser lath-shaped ones remove the stress concentration at the lath tips and consequently benefit improvement of fracture toughness.The article also describes shape evolution of the α-particles during aging thermodynamically and kinetically,and suggests an optimized aging processing to achieve an ideal balance between high strength and high toughness for this alloy.更多还原