摘要
采用基于冷金属过渡焊接的电弧熔丝增材制造技术(CMT-WAAM)制备了Ti-6Al-3Nb-2Zr-1Mo(Ti6321)合金,研究了热处理对Ti6321合金显微组织、力学性能的影响。研究表明,沉积态Ti6321合金组织由不规则的多边形原始β晶和晶界α相(α_(GB))组成,晶内分布有厚度不均的α片层和少量β相。经α+β两相区退火后,α片层内部的位错密度降低,其中,700℃退火后强度和冲击吸收功均有所降低,800℃退火后冲击吸收功提高,且强度达到1050 MPa以上。经双重热处理后析出次生α相(α_(s)),晶界α相(α_(GB))弱化呈断续分布,Ti6321合金冲击吸收功最高达到34 J。不同热处理状态下的冲击断口均有大量韧窝,为典型的韧性断裂。
The effect of heat treatment on microstructure and mechanical properties of Ti-6Al-3Nb-2Zr-1Mo(Ti6321)alloy was studied,which was fabricated by cold metal transfer-wire and arc additive manufacturing(CMT-WAAM).The as-builted microstructure exhibits irregular polygons originalβgrain and grain boundaryαphase(α_(GB)),and the originalβgrain is mainly composed ofαlamellae andβphase.The dislocation density insideαlamellae decreases after heat treatment inα+βphase zone.After heat-treated at 700℃,the tensile strength and impact toughness are decreased.When the heat treatment temperature increases to 800℃,the impact toughness of the samples is increased and the tensile strength is up to 1050 MPa.After double heat treatment,the secondaryαphase is distributed in the transformedβphase,the grain boundaryαphase is broken.The maximum impact toughness of Ti6321 alloy reaches 34 J.The impact fractures under different heat treatment conditions have lots of dimples,which belong to typical ductile fracture.
作者
张帅锋
吕逸帆
魏正英
廖志谦
张建欣
张文豪
Zhang Shuaifeng;Lv Yifan;Wei Zhengying;Liao Zhiqian;Zhang Jianxin;Zhang Wenhao(State Key Laboratory for Manufacturing Systems Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Luoyang Ship Material Research Institute,Luoyang 471039,China)
出处
《钛工业进展》
CAS
2022年第3期11-16,共6页
Titanium Industry Progress
基金
国家重点研发计划项目(2021YFC2800500)
郑洛新自创区产业集群专项(201200211400)。
