Titanium-nickel alloy anti-cavitation thermal spraying powder and method for preparing thermal spraying coating

Abstract

The invention discloses titanium-nickel alloy anti-cavitation thermal spraying powder and a method for preparing a thermal spraying coating and belongs to the technical field of surface engineering. The titanium-nickel alloy anti-cavitation thermal spraying powder working layer is prepared by adopting 58% of nickel-titanium alloy powder and 42% of titanium-coated nickel powder, and a titanium-coated nickel powder transition layer with the thickness of 10 micrometers-2 millimeters is arranged between the working layer and a base body; the bonding strength between the working layer and the basebody is enhanced, a beta-phase structure in the nickel-titanium alloy powder is of a body-centered cubic structure, and particle structures of the nickel-titanium alloy powder and the titanium-coatednickel powder each are of a spherical structure. By using the NiTi alloy beta-phase structure of the body-centered cubic structure, the slippage system in the crystal is reduced, the stress level of the slippage is increased, the surface of the alloy has good wear resistance, and the formed coating has high cavitation resistance, high erosion resistance and high bonding strength and is suitable for large-area use of water conservancy machines.

Description

technical field [0001] The invention relates to the technical field of surface engineering, in particular to a titanium-nickel alloy anti-cavitation thermal spray powder and a method for preparing a thermal spray coating thereof. Background technique [0002] During the operation of hydraulic machinery such as water turbines and pumps, the cavitation generated by rotation will cause serious cavitation wear, damage the surface of mechanical materials, and cause the efficiency and power of hydraulic machinery to decrease. In addition to the cavitation caused by cavitation, sediment erosion will also lead to wear and failure of flow-passing components, forcing the unit to be shut down for overhaul after a period of operation, resulting in huge waste of resources and energy and economic losses. [0003] In order to improve the ability of the flow parts of the turbine to resist sediment wear, spray welding technology is usually used to form a protective layer on the surface of th...

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Problems solved by technology

[0002] During the operation of hydraulic machinery such as water turbines and pumps, the cavitation generated by the rotation will cause serious cavitation wear, damage the surface of mechanical materials, and cause the efficiency and power of hydraulic machinery to decrease.

In addition to the cavitation caused by cavitation, sediment erosion will also lead to wear and failure of flow-passing components, forcing the unit to be shut down for overhaul after a period of operation, resulting in huge waste of resources and energy and economic losses

[0003] In order to improve the ability of the flow parts of the turbine to resist sediment wear, spray welding technology is usually used to form a protective layer on the surface of the turbine. Although a certain effect has been achieved, due to the complex curve of the flow surface of the turbine and the many factors of abrasion and damage to the turbine, it is difficult to Strengthening the anti-abrasion technology of the flow surface of the turbine has brought many difficulties; and because of the complexity of the turbine blade shape and the thick workpiece, it has brought many difficulties to the blade heating process; and the blade stress distribution is complicated, which makes the turbine experience temperature. Deformation of the blade after lifting

Therefore, there are still many insurmountable technical difficulties in the protective coating of water turbines (especially large and medium-sized water turbines) by spray welding technology.

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