源自TB18团簇式优化的高强亚稳β钛合金  

A high strengthβ-Ti alloy optimized from TB18 using cluster formula approach

作　　者：宋志儒 宋梦凡 王清[1] 张爽 董闯[1,2] SONG Zhi-ru;SONG Meng-fan;WANG Qing;ZHANG Shuang;DONG Chuang(School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China;School of Materials Science and Engineering,Dalian Jiaotong University,Dalian 116028,China)

机构地区：[1]大连理工大学材料科学与工程学院,辽宁大连116024 [2]大连交通大学材料科学与工程学院,辽宁大连116028

出　　处：《材料热处理学报》2025年第3期84-92,共9页Transactions of Materials and Heat Treatment

基　　金：沈阳市自然科学基金(22-315-6-05);国家自然科学基金(52101127);辽宁省“兴辽英才计划”项目(XLYC2203121);大连市优秀青年科技人才项目(2023RY040)。

摘　　要：应用团簇式方法,解析出一种典型高强韧亚稳β型TB18钛合金的团簇成分式,由5个α相和12个β相团簇式构成,α-{[Al-Ti_(12)](AlTi_(2))}_(5)+β-{[Al-Ti_(14)](Mo_(5/8)V_(9/8)Cr_(9/8)Nb_(1/8))}_(12),相比于TC4显然该合金含有更多的β稳定元素,这是高强韧性的根源。为了进一步提升β相的稳定性,保持17个团簇总数不变,将β团簇式个数增加到14个,同时提高了β稳定元素含量,设计的团簇式为α-{[Al-Ti_(12)]AlTi_(2)}_(3)+β-{[Al-Ti_(14)]Mo_(5/8)V_(9/8)Cr_(9/8)Nb_(1/8)}_(14),成分为Ti-3.7Al-5.8Mo-5.5V-5.6Cr-1.1Nb。采用非自耗真空熔炼系统制备纽扣锭,随后热轧成板材,将试样在810℃固溶0.5 h后,分别在480、500和520℃时效8 h或24 h。结果表明:合金在480℃时效处理8 h并空冷后达到了强度与延展性的最佳平衡,抗拉强度为1380 MPa,屈服强度为1320 MPa,伸长率为5.5%,与相同热处理工艺下的TB18合金的性能相比,在伸长率保持同水平的基础上,抗拉强度和屈服强度分别提升了50和40 MPa。合金经固溶时效处理后,观察到尺寸为60~120 nm的次生α相析出,且随着时效温度的升高,次生α相发生粗化,强度降低。当时效时间从8 h增加到24 h,次生α相尺寸无明显变化,在520℃下时效24 h时,次生α相析出均匀。Using the cluster formula approach,the cluster composition formula of a typical high-strength and high-toughness metastable β titanium alloy TB18 was analyzed,which consists of 5α-phase and 12β-phase cluster formulas,α-{[Al-Ti_(12)](AlTi_(2))}_(5)+β-{[Al-Ti_(14)](Mo_(5/8)V_(9/8)Cr_(9/8)Nb_(1/8))}_(12).Compared with TC4,this alloy obviously contains moreβ-stabilizing elements,which is the source of high strength and toughness.In order to further enhance the stability of theβ-phase and maintain the total number of 17 clusters unchanged,the number ofβcluster formula was increased to 14,while increasing the content ofβ-stabilizing elements.The designed cluster formulas were α-{[Al-Ti_(12)]AlTi_(2)}_(3)+β-{[Al-Ti_(14)]Mo_(5/8)V_(9/8)Cr_(9/8)Nb_(1/8)}_(14),with a composition of Ti-3.7Al-5.8Mo-5.5V-5.6Cr-1.1Nb.Button ingots were prepared using a non-self-consuming vacuum melting system,followed by hot rolling into plates,and the specimens were solution treated at 810℃for 0.5 h and then aged at 480℃,500℃and 520℃for 8 h or 24 h,respectively.The results show that the alloy reaches the optimal balance between strength and ductility after aging at 480℃for 8 h and air cooling,with a tensile strength of 1380 MPa,a yield strength of 1320 MPa,and an elongation of 5.5%,which is a simultaneous increase in strength and elongation compared with the properties of the TB18 alloy under the same heat treatment process.Specifically,the tensile and yield strengths increase by 50 MPa and 40 MPa respectively,while the elongation remains at the same level.After solution and aging treatment,secondaryα-phase precipitation with a size of 60-120 nm is observed in the alloy,and with the increase of aging temperature,the secondaryα-phase coarsens and the alloy strength decreases.When the aging time increases from 8 h to 24 h,there is no significant change in the size of the secondaryα-phase.However,when aging for 24 h at 520℃,the secondaryα-phase precipitates uniformly.

关 键 词：TB18钛合金 团簇式方法 热处理 力学性能 微观组织 

分 类 号：TG146.2[一般工业技术—材料科学与工程]