(華中科技大學(xué) 材料成形與模具技術(shù)國家重點(diǎn)實(shí)驗(yàn)室，武漢 430074)
摘 要: 為了提高高品質(zhì)液壓油缸的耐磨性能，使用45鋼作為模擬材料，采用YLR-4000型光纖激光器在其表面進(jìn)行激光熔覆，制備NiCrMn+WC復(fù)合涂層。利用金相顯微鏡(OM)和掃描電鏡(SEM)分析其顯微組織和微觀形貌，利用X線衍射儀及能譜分析涂層的相結(jié)構(gòu)和成分，并測(cè)量了其硬度以及磨損性能，獲得最優(yōu)的工藝參數(shù)。結(jié)果表明：激光熔覆層的致密度良好，無明顯的孔洞出現(xiàn)；熔覆層硬度較基體的提高3~5倍，且在一定范圍內(nèi)，隨著掃描速度的增加以及掃描功率的減少，熔覆層的硬度強(qiáng)化效果明顯；硬質(zhì)相的加入使其表面的耐磨性顯著提高，在掃描速度為360 mm/min，功率為2.5 kW，WC含量為30%(質(zhì)量分?jǐn)?shù))時(shí)，熔覆層的各項(xiàng)性能達(dá)到最優(yōu)。
關(guān)鍵字: 液壓油缸；激光熔覆；能量密度；硬度；耐磨性
（Key Laboratory of Material Processing and Die and Mould Technology,
Huazhong University of Science and Technology, Wuhan 430074, China）
Abstract:In order to improve the wear resistance of high-quality hydraulic cylinder, 45 steels were used as the simulative materials, the surface layers NiCrMn-WC composite coatings were fabricated by laser cladding. The microstructure and morphology were analyzed by optical microscopy (OM) and scanning electron microscopy (SEM), the phases and component elements were analyzed by X-ray diffractometry (XRD) and energy dispersive spectrometry (EDS), the microhardness and wear-resistance were tested, and the optimal parameters were obtained. The results show that the appropriate treatment parameters result in good performance of the clad layers with no defects, the microhardness of the CZ is 3-5 times larger than that of the substrate, and the microhardness is promoted as the power reducing and the scanning speed increasing, the wear-resistance is improved with the hard phases adding, each property comes to the best when the power is 2.5 kW, the scanning speed is 360 mm/min and the WC content is 30% (mass fraction).
Key words: hydraulic cylinder; laser cladding; energy density; microhardness; wear-resistance
