| In the current industrial use, the disadvantages of 45 steel after heat treatment are low surface hardness, poor wear resistance, and easily oxidized. These disadvantages limit its further widespread application. Cladding layer with special properties, through the use of high-energy laser beam at the surface alloy powder, can improve the overall performance of the workpiece. The surface modification technique called laser cladding technology. Therefore, laser cladding surface of 45 steel substrate composition prepared near the interface with a solid is become hot recent years, which have the performance of high hardness and wear-resistant, low-cost iron-based.The experiments in this paper were conducted under 45 steel plates. The parameters of mechanical vibration were different with amplitude and frequency. Laser powder and feeding speed were same. And laser cladding synchronous Fe-based self-fluxing powder obtained Fe-Cr-Si alloy cladding. Compare macroscopic and microscopic structure under different vibration parameters of the samples with different vibration parameters. Tissue morphology of cladding layer and substrate materials were observed by OM. Structure and microstructure of cladding coating and field between cladding coating and base were observed by XRD and SEM. What’s more, cladding layer and the substrate between the analysis phase composition and distribution of elements used EDS scan points and lines. And study alloy coating micro hardness analysis using micro-hardness testing instrument. Then simulate analysis cladding facial features under different vibration parameters. Finally, combine elements of different vibration parameters distribution on the interface between cladding layer and substrate. Calculate the relationship between the diffusion coefficient and the concentration of the element and distance. The results show that:1、Within a reasonable range of vibration parameters, a good surface quality can be got. It were metallurgical bond and no macroscopic crack. However, cladding surface appear molten roughness tumors during the increasing of mechanical vibration energy2、According to the characters of mechanical vibration, simulate laser cladding process based on different vibration parameter. As the temperature and stress field result, we can get that: amplitude have the effect on focusing on the center heat source, which increasing pool depth. And frequency have the effect on equalizing the heat source. What’s more, the residual stress field and distribution curve after cooling make us believe that mechanical vibration distribution location for laser cladding residual stress has little effect, but strong amplitude role inclined residual stress on the center of the cladding. it the show that vibration makes sustained release effect on laser cladding.3、Iron-based alloy powder in the laser cladding process may be formed to α-Fe or γ-Fe alloy carbide substrate (Fe, Cr)7C3, (Fe, Cr)23C6 and represented by a small amount to Fe2B borides. These carbides and borides are all with high strength and hardness. As mechanical vibration energy calculations, the changes of the amplitude play a important role in excitation energy and it is more obvious more positive than frequency.4、There is 2～3 μm dark band structure between cladding layer and substrate in laser cladding microstructure, which is due to imbalance diffusion effects of Cr, Si and other element. This article measures at the interface Fe-(Cr, Si) diffusion of Cr, Si element concentration profile and calculate the diffusion coefficient. The result show that diffusion coefficient at same point can decrease by mechanical vibrations. And the diffusion coefficients of Cr, Si elements in the interface are change with temperature gradient and concentration. What’ more he impact of the vibration amplitude parameters of the diffusion coefficient is greater than the frequency. |
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