TC18钛合金固溶过程中黑斑组织的形成机理  

Formation Mechanism of Black Flecks During Solution Treatment of TC18 Titanium Alloy

作　　者：朱雪峰[1] 周瑜 樊凯 王柯[2] ZHU Xuefeng;ZHOU Yu;FAN Kai;WANG Ke(Hunan Goldsky Titanium Technology Co.,Ltd.,Changde 415001,China;School of Materials Science and Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]湖南金天钛业科技有限公司,常德415001 [2]重庆大学材料科学与工程学院,重庆400044

出　　处：《材料导报》2020年第S01期289-292,共4页Materials Reports

基　　金：国家自然科学基金(51971046)。

摘　　要：TC18钛合金棒材在相变点以上固溶处理后,低倍下出现了不均匀的黑斑组织。本研究结合光学显微镜、扫描电镜、电子背散射衍射等多种表征手段,对黑斑组织进行了精准表征。同时结合热处理实验,探明了黑斑组织的形成机理。研究表明:黑斑组织沿着棒材中心至边缘处逐渐减少。黑斑组织内部析出了大量的针状α相,且呈现出大块聚集的形貌。这是因为固溶过程中,未发生完全再结晶的大块β晶粒内部产生了亚晶和残留了一定量的位错,且由于中心位置冷却速度较慢,从而促进了次生α相的析出,进而呈现出黑斑特征。During the solution treatment of TC18 titanium alloy in the singleβphase region,the black fleck formed and acted as a heterogeneous microstructure.Many characterization methods,such as optical microscope(OM),scanning electron microscope(SEM),electron back-scattered diffraction(EBSD),and so on,were used to make a precise characterization on the black fleck.Meanwhile,some additional heat treatments were carried out for revealing the formation mechanism of black fleck.The results showed that the massive precipitation of acicularαphase made theβgrain exhibit as a black fleck morphology,and the black fleck existed as a large and accumulated morphology.During solution treatment,accompanying a slow cooling rate in the center region of the TC18 titanium alloy bar,the formation of subgrain and remnant dislocation in the non-completed recrystallizedβgrain promoted the precipitation of acicularαphase.

关 键 词：TC18钛合金 黑斑 再结晶 次生α相 

分 类 号：TG146.23[一般工业技术—材料科学与工程]