钢铁钒钛2026，Vol.47Issue(2)：71-77,7.DOI:10.7513/j.issn.1004-7638.2026.02.009
基于相变调控的Ti551钛合金热处理工艺优化
Optimization of heat treatment process for Ti551 titanium alloy based on phase transformation regulation
摘要
Abstract
The effects of heat treatment parameters including solution temperature,aging temperature and cooling rate on the microstructure and mechanical properties of a new medium-strength and high-toughness Ti551 alloy were investigated by means of optical microscopy,scanning electron microscopy and universal tensile testing machine.With the same solid solution temperature at 900℃,no obvious changes were observed in the content and size of primary α phase of alloy,while the lamellar thickness of secondary α phase increased from 0.26 μm to 0.42 μm with the aging temperature increasing from 550℃to 650℃.With the same aging temperature of 550℃,the content of the primary α phase de-creased from 45%to 15%as the solution temperature increased from 900℃to 950℃,along with con-tinuous refinement of grains and morphological transformation from short rod-like to equiaxed.The lamellar thickness of the secondary α phase increased accordingly,reaching up to 0.72 μm after alloy subject to solid solution treatment at 950℃.The morphological feature and size of the microstructure are decisively influenced by the cooling rate:an almost single fully equiaxed primary α phase micro-structure is obtained by furnace cooling,whereas the primary α phase is refined and the precipitation of coarse lamellar secondary α phase is promoted by moderate cooling.The results show that optimal strength-toughness combination of the Ti551 alloy is achieved under the composite heat treatment of 900℃×2 h+air cooling,then followed by 550℃×6 h aging,which is closely associated with the regu-latory role of cooling rate.Acicular secondary α phase can be induced in the transformed β microstruc-ture by higher cooling rate,and the alloy's strength-plasticity matching effect is further enhanced by the subsequent aging treatment.关键词
Ti551钛合金/热处理/微观组织/力学性能Key words
Ti551 titanium alloy/heat treatment/micro-structure/mechanical properties分类
矿业与冶金引用本文复制引用
王永锋,申宇波,张宏岭,栾佰峰,周思源,马英杰..基于相变调控的Ti551钛合金热处理工艺优化[J].钢铁钒钛,2026,47(2):71-77,7.基金项目
国家重点研发计划(2024YFB3714200). （2024YFB3714200）
