Study On Microstructure And Properties Of TiC Reinforced Ni-Fe-Al By Laser Cladding

The rapid development of industrial puts a higher demand on the performance of the material.Preparation of new materials with high quality is important for its application.The laser 3D printing technology provides a new preparation method of new materials.The laser 3D printing technology has its own unique advantages in the preparation of ceramic particles reinforced metal matrix composites.The laser 3D printing takes use of the characteristic of the micro zone melting and the rapid solidification and the problem of segregation and agglomeration of the ceramic powders melting can be avoided,which can significantly improve the quality of the preparation of materials.Therefore,based on 3D printing technology,this thesis researched the preparation mechanism of ceramic reinforced metal matrix composite,by carrying out a series of laser cladding process test of Ni-Fe-Al reinforced with different content of TiC ceramic particles powder on stainless steel and nickel-based alloy plate.In this thesis,the influence of laser cladding parameters on macroscopic morphology and microstructure of cladding layers was investigated by changing the parameters such as laser power,laser frequency,laser scanning speed and defocus amount,etc.The test equipment of laser scanning confocal microscope(LSCM),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS)and X-ray diffraction(XRD)were used to investigate the microstructure and the phase composition of the cross section.The hardness and the wear resistance of cladding section was characterized and analyzed by Vickers hardness tester and friction and wear tester.The main work and conclusions are as follows.(1)The laser cladding process was explored.The influence of single process parameters on cladding quality was studied by using the single factor method.The effect rule of laser cladding process parameters on the cladding quality was found,and the optimized combination of laser cladding process parameters was obtained.The single-line cladding of ceramic reinforced metal matrix composite with good surface morphology were prepared on the surface of stainless steel and nickel-based alloy substrate,Respectively.(2)The macroscopic morphology and microstructure of the prepared samples were observed and characterized by LSCM,SEM,EDS,XRD.It was found that the single-channel cladding strip with a good morphology and a fine metallographic structure and an enhanced phase dispersion could be prepared by laser cladding.(3)The hardness,the friction and the wear properties of the samples were tested by taking use of Vickers hardness tester,friction and wear tester.It was found that the hardness of the cladding stripe increased,however the bottom wear resistance of the cladding stripe decreases with the increasing of the proportion of TiC powder.TiC ceramic particles reinforced Ni-Fe-Al composites with dense structure and no obvious defects were prepared by optimized laser cladding process parameters in this thesis.The feasible to prepare ceramic reinforced metal matrix composites by laser 3D printing technology was described.