Electric arc rapid molding method

Abstract

The invention provides an electric arc rapid molding method. The electric arc rapid molding method comprises the following steps: step 1, connecting a TIG welding gun and a rapidly molded workpiece with a power supply, guiding heat transferring electric arcs between the welding gun and the rapidly molded workpiece, and forming a molten bath on the workpiece; step 2, disconnecting the rapidly molded workpiece from the power supply so as to extinguish the heat transferring electric arcs, conveying a welding wire forwards by a wire conveying mechanism, connecting the welding wire with the power supply, guiding mass transferring electric arcs between the welding gun and the welding wire, and after melting the welding wire, carrying out molten drop transition in the molten bath; step 3, disconnecting the welding wire from the power supply so as to extinguish the mass transferring electric arcs, and drawing the welding wire back by the wire conveying mechanism so as to bring the welding wireaway from the heat transferring electric arc zone; and step 4, rapidly cyclically repeating the steps. Heat transferring and mass transferring processes are separate, so that heat input and the melting speed of the welding wire can be separately controlled. The heat input of the rapidly molded workpiece and the size of the molten bath can be controlled by the arc combusting time and current density of the heat transferring electric arcs, so that the input of excessive heat into the workpiece is avoided. The melting speed of the welding wire and the size of molten drops can be controlled by the arc combusting time and current density of the mass transferring electric arcs, and the molding efficiency is ensured.

Description

technical field [0001] The invention relates to an arc rapid prototyping method. Background technique [0002] Arc rapid prototyping technology uses electric arc as heat source, based on the "discrete-stack" principle, using three-dimensional CAD data, using point-by-point and layer-by-layer forming methods to manufacture molds or parts, etc. An advanced manufacturing technology, due to the short processing cycle, Good performance, low cost, good controllability, unlimited molding shape and materials, etc., have become the key technologies for efficient and flexible production today. The traditional arc rapid prototyping is the combination of 3D printing technology and arc welding. The TIG welding torch is installed on the working head of the 3D printer. , through the arc striking between the welding torch and the base metal to form a molten pool on the base metal, then extend the welding wire into the arc between the welding torch and the base metal, and use the high tempe...

AI Technical Summary

Problems solved by technology

When this method is used, the same arc maintains heat transfer and mass transfer, and the heat transfer and mass transfer process cannot be controlled separately; increasing the arc current can ensure the melting speed of the welding wire and the molding efficiency, but at the same time it increases the heat input of the formed workpiece, and the heat Accumulation may make the workpiece soft and collapse, which will affect the forming. At the same time, too much heat input will cause the grain of the formed workpiece to be coarse, which will reduce the mechanical energy. On the contrary, if the arc current is reduced, the forming efficiency will be affected.

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