(大連理工大學(xué) 材料工程系， 大連 116023)
摘 要: 選用合適的激光工藝參數(shù)及涂層成分，利用激光熔覆工藝在45＃鋼表面制備了原位析出Fe-Ti-B復(fù)合材料涂層。遠離平衡態(tài)的激光表面處理工藝使涂層中原位析出了一定數(shù)量的不同于穩(wěn)定相的亞穩(wěn)定相。 利用X射線衍射（XRD）、 透射電鏡(TEM)等手段對涂層的顯微組織及相結(jié)構(gòu)進行了研究。 結(jié)果表明：涂層中主要含有呈塊狀、 條狀、 顆粒狀或團絮狀分布的Fe2B(Fe3B)/α-Fe和TiB2(TiB)/α-Fe低熔點共晶或離異共晶組織； 原位共晶相析出時與基體保持某種最合理的空間取向， 在α-Fe基體與原位析出相界面上存在隱約可見的位錯堆積。
關(guān)鍵字: 激光熔覆； Fe-Ti-B; 原位析出； 涂層； 顯微組織
（ Department of Materials Engineering，
Dalian University of Technology， Dalian 116023, China）
Abstract: In-situ precipitating Fe-Ti-B composite coating was fabricated on 45# steel surface by laser cladding with optimal laser parameters and coating compositions. A certain amount of metastable phases differing from the stable phases were obtained through laser surface modification which deviates from the equilibrium state. The microstructure of the coating was studied by X-ray diffractometry(XRD) and transmission electron microscopy(TEM). The results show that the coating mainly contains Fe2B(Fe3B)/α-Fe and TiB2(TiB)/α-Fe low melting point eutectic or divorced eutectic presenting block, strip, granular and wadding shape. The in-situ eutectic phases and the matrix have a certain optimal orientation relationship as they precipitate. The faint dislocation tangle lies at the interface between the matrix and the in-situ precipitating phases.
Key words: laser cladding; Fe-Ti-B; in-situ precipitating; coating; microstructure
