Temperature field control method in laser additive manufacturing process

Abstract

The invention relates to the field of metal component additive manufacturing, in particular to a temperature field control method in the laser additive manufacturing process. The method comprises the following steps that firstly, metal powder for the impeller and heterogeneous nucleation refiner powder are mixed; secondly, slicing software is used for conducting slicing and scanning path area discretization planning on the digital model of the impeller component to be formed; thirdly, laser energy input is changed into discontinuous input according to a planned scanning path; and fourthly, laser additive manufacturing is conducted. In-situ preheating and resistance tape or resistance wire heating in the laser additive manufacturing process are combined together, heat preservation is conducted through heat preservation sand or heat preservation cotton, the temperature gradient in a component to be manufactured or remanufactured can be reduced, residual stress can be reduced, and regulation and control over the microstructure of a formed part can be achieved by controlling the heating temperature. The method is high in applicability, not only can be used for additive manufacturing of the metal component, but also can be used for repairing and remanufacturing of the metal component.

Description

Technical field: [0001] The invention relates to the field of additive manufacturing of metal components, in particular to a method for controlling a temperature field in a laser additive manufacturing process. Background technique: [0002] Laser additive manufacturing technology uses a high-energy-density laser beam as a heat source to achieve near-net manufacturing and repair and remanufacturing of parts through point-by-point, line-by-line, and layer-by-layer superposition. At present, laser additive manufacturing technology has been applied to many metal components, such as: titanium alloys, superalloys, aluminum alloys, copper alloys, steel. In the process of additive manufacturing, a tiny metal molten pool solidifies on a relatively large solid matrix, and the solidification shrinkage is limited, resulting in a certain internal stress around the molten pool. At the same time, since additive manufacturing is heated and melted in a local area, the temperature of differ...

AI Technical Summary

Problems solved by technology

Moreover, with the progress of the additive manufacturing process, due to the accumulation of more and more heat in the formed component, the temperature gradient of the laser melt pool when the bottom of the component is formed is different from the temperature gradient of the molten pool when the top is formed, resulting in It is different from the microstructure of the top, which affects the performance of the component

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