Electro-thermal spraying is a method for melting, vaporizing and expanding conductors with powerful pulsed current, causing explosion, generating shock wave mechanical effect and spraying blast products to substrate surface at high speed to form coating. Most electroexplosive spraying materials are made of silk, such as Ni wire, Mo wire, Cu wire, ZnO wire, etc. Part of the foil as a spraying material for spraying. As most spraying materials exist in the form of powder, therefore, using powder as spraying materials has certain application advantages. Powder electro-explosive spraying first powder is burned into wire as the spraying material, or powder into aluminum oxide tube into powder column after spraying on the inner wall of tube workpiece. These spraying methods for circular tubes have certain limits on the spraying distance, which can only be the radius of the tube. In order to effectively control spraying distance during the spraying process, the literature to study the directional spraying powder, the powder into the inner layer of insulating tube and outer metal sleeve tube in the container, the container side open a window, thus limit of spraying direction, explosion product pouring out the impact from the window to the substrate surface coating.

The tungsten carbide powder was prefabricated on the matrix by hydraulic press and simple die, and the prefabricated layer was fused by high-power CO_2 laser. The temperature field of laser surface cladding is simulated by APDL parameter language of ANSYS, and the parameters range of laser surface cladding process is predicted. In this paper, a hard alloy powder composed of ferroalloy powder, tungsten carbide powder and cobalt powder is selected. With Q235 ordinary carbon steel as the matrix, a hole about 1.5mm deep is directly milling on the matrix metal to form a pressing die. A simple punch is designed and a reasonable pressing process is established. A universal hydraulic press is used to press the hard alloy powder pre-installed in the mould onto the matrix, and a certain strength and thickness are obtained, and a preset layer of mechanical engagement is formed with the matrix. Tj-hl-t5000 5kw cross-flow CO_2 laser machine was used to determine the processing power of 2600W and spot width of 13mm. Based on the theory of laser cladding limit thickness, the maximum limit scanning speed is calculated and the tentative scanning speed is set down. In laser cladding, the optimum process parameters are obtained by fixing the power, changing the spot size and changing the scanning speed.

Hide Comments | Add Comment