Dilution effect on the formation of amorphous phase in the laser cladded Ni-Fe-B-Si-Nb coatings after laser remelting process

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• 作者：Ruifeng Li^a ; ^b ; Zhuguo Li^a ; ^{lizg@sjtu.edu.cn} ; Jian Huang^a ; Yanyan Zhu^a
• 关键词：High power diode laser ; Laser cladding ; Remelting ; Amorphous coating ; Dilution
• 刊名：Applied Surface Science
• 出版年：2012
• 期刊代码：6_01694332
• 类别：ms
• 出版时间：1 August, 2012
• 卷：258
• 期：20
• 页码：7956-7961
• 文件大小：2243 K

摘要

Ni-Fe-B-Si-Nb coatings have been deposited on mild steel substrates using high power diode laser cladding. Scanning laser beam at high speeds was followed to remelt the surface of the coatings. Different laser cladding powers in the range of 700-1000 W were used to obtain various dilution ratios in the coating. The dilution effect on the chemical characterization, phase composition and microstructure is analyzed by energy dispersive spectroscopy, X-ray diffraction and scanning-electron microscopy. The microhardness distribution of the coatings after laser processing is also measured. The results reveal that Ni-based amorphous composite coatings have successfully been fabricated on mild steel substrate at low dilution ratio when the cladding power was 700 W, 800 W and 900 W. While at high laser power of 1000 W, no amorphous phase was found. The coatings with low dilution ratio exhibit the highest microhardness of 1200 HV_0.5 due to their largest volume fraction of amorphous phase.