(1. 常州大學(xué) 機(jī)械工程學(xué)院，常州 213164；
2. 常州大學(xué) 江蘇省綠色過(guò)程裝備重點(diǎn)實(shí)驗(yàn)室，常州 213164)
摘 要: 以Cr12MoV冷模具鋼為研究對(duì)象，采用不同的激光功率密度在Cr12MoV表面熔覆WC質(zhì)量分?jǐn)?shù)為40%的Ni60WC40復(fù)合涂層。隨后對(duì)熔覆后試樣的涂層熔覆界面、熔覆表面微觀(guān)組織和成分的形成進(jìn)行探討，并通過(guò)摩擦磨損實(shí)驗(yàn)研究各熔覆層的耐磨損性能。結(jié)果表明：隨著激光熔覆功率密度的提高，熔覆層厚度逐漸增大，熔覆區(qū)縱向組織從尚未完全熔化的團(tuán)絮狀及棒狀晶逐漸向晶粒更為細(xì)小的花瓣晶轉(zhuǎn)變；熔覆區(qū)橫向組織從長(zhǎng)短不一的花瓣晶及魚(yú)骨狀樹(shù)枝晶逐漸向晶粒尺寸更為細(xì)小的長(zhǎng)條形枝晶轉(zhuǎn)變；CrNiC、CrFeNi等鉻碳化合物和WN、CoN等金屬固溶體的產(chǎn)生增強(qiáng)涂層的細(xì)晶強(qiáng)化作用。在激光功率密度為111.30 W/mm2時(shí)，試樣表現(xiàn)出相對(duì)最優(yōu)的耐磨性能。
關(guān)鍵字: 激光熔覆；熔覆區(qū)；摩擦；磨損；Ni60WC40
（1. School of Mechanical Engineering, Changzhou University, Changzhou 213164, China;
2. Jiangsu Key Laboratory of Green Process Equipment, Changzhou University, Changzhou 213164, China）
Abstract:The composite coatings of Ni60WC40 (mass fraction, %) were cladded on Cr12MoV mold steel by laser cladding with different power density. The interface and surface microstructure of cladded coatings and the surface composition were investigated, and moreover, the wear resistance of cladded coatings was tested. The results indicate that the thickness of cladded coating increases with the raising of laser cladding power density. In addition, the unmelted flocculent and rod-shaped crystals, which are in the longitudinal microstructure of the cladded zone, gradually transforms to the finer petal crystals. The lateral microstructure of cladded coating is transferred from petal crystals with various sizes and fishbone dendrites to long strip dendrites with finer grain size. The generation of chromium carbons (CrNiC, CrFeNi, etc.) and metal solid solution (WN, CoN, etc.) improves the coatings strengthened subjected to the fine grain. With 111.30 W/mm2 of laser power density, the coating performs the best running-in tribological behaviors.
Key words: laser cladding; cladded zone; friction; wear; Ni60WC40
