Influence of Scanning Speed on Microstructure and Properties of Laser Cladded Fe-Based Amorphous Coatings.

Xiangchun Hou,Ninshu Ma,Baohua Chang,Dong Du

doi:10.3390/ma12081279

Xiangchun Hou, Ninshu Ma + Show 2 more

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https://doi.org/10.3390/ma12081279

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Abstract

Fe-based amorphous alloys with excellent mechanical properties are suitable for preparing wear resistant coatings by laser cladding. In this study, a novel Fe-based amorphous coating was prepared by laser cladding on 3Cr13 stainless steel substrates. The influence of scanning speeds on the microstructures and properties of the coatings was investigated. The microstructure compositions and phases were analyzed by scanning electron microscope, electron probe microanalyzer, and x-ray diffraction respectively. Results showed that the microstructures of the coatings changed significantly with the increase of scanning speeds. For a scanning speed of 6 mm/s, the cladding layer was a mixture of amorphous and crystalline regions. For a scanning speed of 8 mm/s, the cladding layer was mainly composed of block grain structures. For a scanning speed of 10 mm/s, the cladding layer was composed entirely of dendrites. Different dilution rates at the bonding zones were the main reasons for the microstructure change for different claddings. For all three scanning speeds, the coatings had higher hardness and wear resistance when compared with the substrate; as the scanning speed increased, the hardness and wear resistance of the coatings gradually decreased due to the change in microstructure.

Highlights

Amorphous alloys have unique properties such as high hardness, high strength, high wear resistance, and high corrosion resistance because of their short-range order and long-range disordered structure [1,2,3]
The main objective of this study was to investigate the effects of scanning speeds on microstructure and properties of the coatings
When the scanning speed was 6 mm/s, a broad halo peak characterizing an amorphous phase could be observed at the diffraction angle around 44◦, on which sharp diffraction peaks corresponding to the carbides

Summary

Introduction

Amorphous alloys have unique properties such as high hardness, high strength, high wear resistance, and high corrosion resistance because of their short-range order and long-range disordered structure [1,2,3]. Their unique properties make amorphous alloys suitable for surface coatings. Different processes have been used to prepare surface coatings such as laser cladding, plasma spray, spark cladding, and high velocity oxygen fuel (HVOF) [4,5,6,7,8]. Laser cladding can meet the requirements of preparing amorphous alloys thanks to its rapid cooling characteristics. Laser cladding has attracted more and more attention in the fabrication of amorphous surface coatings

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Results

Conclusion