摘要
运用 5kWCO2 连续激光器在低碳钢表面激光熔覆Co基合金涂层 (Co5 5 )及Co基合金中添加 2 0 %B4C(体积分数 )的复合涂层 (B4C/Co) ,研究了B4C对熔覆层组织、显微硬度及耐磨性的影响。结果表明 ,两种熔覆涂层均为树状枝晶生长的亚共晶组织。Co5 5涂层主要由大量初生枝晶γ固溶体及其间的共晶组织γ与 (Cr,Fe) 7C3 组成 ;B4C/Co涂层主要由γ -Co ,Cr7C3 ,Cr2 3 C6,CrB2 和Fe2 3 (C ,B) 6组成 ,添加的B4C粒子在熔覆过程中全部熔解 ,但B4C/Co涂层组织与Co5 5相比明显细化。B4C/Co涂层的显微硬度及耐磨性比Co5 5涂层都明显提高 。
Laser cladding of Co55 Co-based alloy and Co-based alloy with 25vol% B4C(B4C/Co) on low carbon steel substrate is performed by 5 kW CO2 continuous wave laser. The effects of B4C particles on microstructure, microhardness and wear resistance of Co-based alloy coating are investigated. The results show that the microstructure of the two coatings is the dendrites of subeutectic structure. Co55 coating consists of γ-Co and (Cr, Fe)7C3, and B4C/Co coating consists of γ-Co, Cr7C3, Cr23C6, Fe23 (C,B)6 and CrB2. B4C particles are completely dissolved in the Co-based alloy during the laser cladding. The dendrites of the B4C/Co coatings are much finer than that of the Co55 coating. Microhardness and sliding wear resistance of the B4C/Co coating are higher than that the Co55 coating. The strengthening mechanism of the coatings is analyzed.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2004年第3期61-64,共4页
Transactions of The China Welding Institution
基金
中韩国际合作项目 ( 2 0 0 2KJ0 5 8ZD)
安徽省教育厅自然科学研究项目 ( 2 0 0 3KJ0 5 8)
关键词
激光熔覆
钴基合金涂层
B4C
组织
耐磨性
Boron carbide
Coatings
Laser applications
Metal cladding
Microhardness
Wear resistance
