Study On Microstructure And Properties Of Alloy Coatings By Laser Cladding AlFeMnSi System Multi-principal Element Alloys On Aluminum Alloy

Aluminum alloy are widely used in industries because of their outstanding properties, such as easy processing, low density but high specific strength and specific stiffness. However, there are some defects, such as low surface hardness、high friction coefficient and big wearing and so on, which have badly limit the application of aluminum alloy. We can obtain compact coatings with great binding performance on the surface of Aluminum alloy by laser cladding, and the grains are very small. Compared with the traditional cladding material, multi-principal element alloys breaks through the design concept of the traditional alloy, they are consist of a variety of main elements. The wetting phase and the ratio of hard phase and ductile phase can get adjust in a wide range through the composition changes. The paper adopt the technology of laser cladding to produce Al-Fe-Mn-Si system multi-principal element alloys coatings on the surface of aluminum alloy, and research the laser cladding process 、 the macro morphology 、 phase 、 microstructure、micro-hardness and wear resistance of cladding layer.The ideal range of process preparing Al-Fe-Mn-Si system multi-principal element alloys coatings by YAG laser on the surface of 6061 aluminum alloy are: V=4~5mm/s、pm=5~6kw、tp=6~8ms、D=4~5mm、f=8HZ.The results show that, It can obtain coating with great macroscopic quality on the surface of aluminum alloy with optimized technique. The cladding layer are composed of equiaxed crystal and dendrite crystal, planar crystal appear in the transition zone. AlFeMnSiZn and AlFeMnCoCrSix multi-principal element alloys coatings by laser are mainly composed of α-Al which is simple FCC solid-solution. A little amount of intermetallic compounds Al13Fe4, Al6 Mn appeared in AlFeMn SiZn multi-principal element alloys coatings, and There are Al8Fe2 Si, Al13Fe4, Al6 Mn in AlFeMnCoCrSix multi-principal element alloys coatings, and the less content of Si element, the more intermetallic compounds. The surface micro hardness of AlFeMnSiZn multi-principal element alloys coatings can reach 330 HV0.2, which is 3 times compared to that of the matrix.The hardness of AlFeMnCoCrSix coatings has increased by nearly 3~7 times than matrix, The tendency of hardness: AlFeMnCoCrSi0.1> AlFeMnCoCrSi0.7>AlFeMnCoCrSi1>AlFeMnCoCrSi0.4. The research of wear test results show that, the wear volume of AlFeMnSiZn multi-principal element alloys coatings is as 1/4 as it of the matrix, the mechanism follows abrasive wear and adhesive wear.to the AlFeMnCoCrSix multi-principal element alloys coatings, it is mainly abrasive wear and it appears flake phenomenon, the wear volume of AlFeMnCoCrSix coatings are 0.14~0.34 times in comparison to the substrate. Among them, the proportion of ductile phase and hard particles of AlFeMnCoCrSi0.7 multi-principal element alloys coatings are the most appropriate,so its wear resistance is the most outstanding.