文章信息/Info

Title:

Effect of Heat Treatment on Microstructure and Properties of Ti2 AlNb Alloy Fabricated by Selective Electron Beam Melting

文章編號:

1674-3962(2023)06-0499-07

作者:

李會霞1;  車倩穎1;  賀衛衛1; 2;  向長淑1; 2;  程康康1;  王　宇1

1. 西安賽隆增材技術股份有限公司, 陜西 西安 710018 2. 西北有色金屬研究院 金屬多孔材料國家重點實驗室, 陜西 西安 710016

Author(s):

LI Huixia1;  CHE Qianying1;  HE Weiwei1; 2;  XIANG Changshu1; 2; CHENG Kangkang1;  WANG Yu1

1. Xi‘an Sailong AM Technologies Co. , Ltd. , Xi‘an 710018, China 2. State Key Laboratory of Porous Metals Materials, Northwest Institute for Nonferrous Metal Research,Xi’an 710016, China

關鍵詞:

Ti2 AlNb 合金;  增材制造;  電子束選區熔化;  顯微組織;  力學性能

Keywords:

Ti2AlNb alloy;  additive manufacturing;  selective electron beam melting; microstructure;  mechanical properties

分類號:

TG156; TG146. 23

DOI:

10.7502/j.issn.1674-3962.202203024

文獻標志碼:

A

摘要:

采用電子束選區熔化(selective electron beam melting, SEBM)成形技術制備了高致密的Ti2 AlNb 合金試樣, 并以此Ti2 AlNb 合金試樣為對象, 系統研究了它在不同熱處理制度下的顯微組織及物相組成, 并對其硬度、室溫及650 ℃ 拉伸性能以及斷口形貌進行了分析表征。結果表明, 電子束選區熔化成形Ti2 AlNb 合金熱處理態試樣的微觀組織主要由B2 基體相、晶粒尺寸較大的板條狀初生O/ α2 相和細小的次生針狀O 相組成, 950 ℃ 固溶+700 ℃ 時效試樣的次生針狀O 相和α2 相含量較高, 950 ℃固溶+800 ℃時效試樣的初生O/ α2 板條更為粗大。700 和800 ℃時效熱處理制度下Ti2 AlNb 合金試樣的顯微硬度值接近, 為3190~3210 MPa。950 ℃固溶+700 ℃ 時效處理試樣的室溫和650 ℃ 抗拉強度最高, 分別為(1068±12. 22) MPa 和(843±39. 72)MPa; 而950 ℃固溶+800 ℃ 時效處理試樣的室溫和650 ℃ 下的延伸率更高, 分別為(7. 30±0. 58)%和(8. 50±0. 50)%。950 ℃固溶+700 ℃時效試樣的室溫拉伸斷口觀察到較大尺寸的裂紋, 時效溫度提高到800℃ 后, 裂紋消失, 高溫拉伸斷口呈現出韌性斷裂特征。

Abstract:

In this paper, Ti2AlNb alloy samples fabricated by selective electron beam melting (SEBM) technology were treated with different heat treatment systems. The microstructure and phase composition of heat-treated samples were analyzed,the microhardness, tensile properties at room temperature and 650℃ and fracture morphology of the samples were evaluated.The results indicate that the microstructure of the heat-treated samples is mainly composed of B2 matrix phase,lath-like primary O/ α2 phase with large grain size and fine secondary needle O phase. Ti2AlNb alloy samples after 950 ℃ solution treatment and 700 ℃ aging treatment exhibit more needle-like O phase and α2 phase. The lath O/ α2 phase of samples after 800 ℃ aging treatment is coarsened to some extent. The heat-treated samples exhibit a microhardness of 3190 ~ 3210 MPa. After aging treatment at 700 ℃, the samples show a higher ultimate tensile strength of (1068±12. 22) MPa and (843±39. 72) MPa at room temperature and 650 ℃ respectively. After aging treatment at 800 ℃, the samples show better tensile elongation of (7. 30±0. 58)% and (8. 50±0.50)% at room temperature and 650 ℃ respectively. After aging treatment at 700 ℃, the tensile fracture of the samples at room temperature exists cracks with large size. From the tensile fracture of samples after aging treatment at 800 ℃, no crack is found. Tensile fracture at high temperature shows a large number of dimples, exhibiting ductile fracture characteristics.