摘要
以热压烧结碳化钨(WC)和气体渗碳WC涂层为研究对象,利用原位扫描电镜、X射线能谱仪、电子背散射衍射仪、X射线衍射仪和拉曼光谱仪表征材料的显微形貌、元素组成、晶体取向、物相结构及分布。分析结果表明,涂层截面含有WC、W_(2)C和非晶相。WC主相晶粒尺寸约3μm,厚度约15μm,呈六方多晶状,其拉曼光谱主峰位与WC特征峰位(A_(1)110cm^(-1)、A_(2)166cm^(-1))相吻合,峰形和峰位与热压烧结WC一致;WC晶粒沿(101)晶面生长,出现择优取向,在拉曼光谱中表现为75cm^(-1)峰强度变大,与XRD结果相吻合。W_(2)C晶体结构为六方相,在涂层中存在两种形貌,靠近表层为细小晶粒均匀分布区,靠近基体为单晶异常生长区;W_(2)C区拉曼光谱的主峰位与W_(2)C拉曼特征峰位(E_(g)128.5cm^(-1)、A_(1g)220cm^(-1))吻合,并与WC主峰无干扰。非晶带位于W_(2)C细晶区与基体之间,宽度约2μm,含有摩尔分数约2%的Fe杂质元素,其拉曼光谱表现为无峰的鼓包,与其他相较好地区分开。涂层的拉曼光谱分析验证了电子背散射衍射获得的物相分布结果,丰富了涂层材料截面的物相结构信息。由于电子背散射衍射制样复杂,拉曼光谱在快速鉴定WC、W_(2)C和非晶相中具有不可替代的优势。
Taking hot-pressed sintered tungsten carbide(WC)and gas carburized WC coatings as the re-search objects,their microstructure,element composition,crystal orientation,phase composition and distri-bution were characterized by in-situ SEM,EDS,EBSD,XRD and Raman spectrometer.The analysis results show that the coating cross-section contains WC,W_(2)C and amorphous phase.The grain size of WC main phase is about 3μm,the thickness is about 15μm,and it is hexagonal and polycrystalline.The main peak positions in Raman spectrum of WC layer are consistent with the characteristic peak positions of WC(A_(1)110cm^(-1) and A_(2)166cm^(-1)),and the peak shape and position are consistent with those of sintered WC.WC grains grow along(101)crystal plane,showing apreferential orientation and resulting in increased intensi-ty of 75cm^(-1) Raman peak,which is consistent with XRD results.The crystal structure of W_(2)C is hexago-nal,and there are two kinds of W_(2)C microstructures in the coating:Fine grains of uniform distribution are near the surface layer and the abnormally grown single crystals are near the substrate.The main Raman peak positions of W_(2)C area are consistent with W_(2)C characteristic peak positions(E_(g)128.5cm^(-1) and A_(1g) 220cm^(-1)),and they have no interference with WC main peaks.The amorphous layer with a width of about 2μm is located between the W_(2)C fine-grained area and the substrate,and it contains about 2%(molar frac-tion)Fe impurity.Raman spectrum of the amorphous layer shows peakless bulge,which is well distin-guished from other phases.Raman spectrum analysis of the coating verifies the phase distribution results obtained by EBSD,and the phase composition information of the coating material cross-section is enriched.Due to the complexity of EBSD sample preparation,Raman spectrum has an irreplaceable advantage in the rapid identification of WC,W_(2)C and amorphous phase.
作者
王丁丁
马贤
王筠
安晓娇
WANG Ding-ding;MA Xian;WANG Jun;AN Xiao-jiao(Institute of Laser Technology,Institute of Physical and Chemical Engineering of Nuclear Industry,Tianjin 300180,China)
出处
《稀有金属与硬质合金》
CAS
CSCD
北大核心
2022年第1期37-41,51,共6页
Rare Metals and Cemented Carbides
作者简介
通信作者:王丁丁(1985-),女,硕士,高级工程师,主要研究方向为金属陶瓷复合材料制备及材料分析检测,E-mail:ipce_wangding@163.com。
