Interlayer ultrasonic peening assisted high-performance CMT electric arc additive manufacturing method and device

[0024] The specific embodiments of the present invention are described below to facilitate those skilled in the art to understand the present invention, but it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes Such changes are obvious within the spirit and scope of the present invention as defined and determined by the appended claims, and all inventions and creations utilizing the inventive concept are within the scope of protection.

[0025] In the invention, ultrasonic impact treatment is performed on the interlayer bonding interface in the CMT arc additive manufacturing process, so as to eliminate the residual tensile stress at the interface and make the forming surface of the component uniformly plastically deform. The periodicity of equiaxed crystals is uniformly distributed, thereby effectively blocking the growth of coarse columnar β-crystals, improving the anisotropy of components, and simultaneously improving the strength and toughness of arc additive components.

[0026] like figure 1 Shown is a schematic diagram of the overall device structure of the present invention, figure 2 It is a partial enlarged schematic diagram of the working area, which mainly includes two parts: the cold metal transition arc additive control device and the harmonic ultrasonic impact control device. The cold metal transition arc additive control device can flexibly control the three-coordinate movement of the welding torch 1, such as the feeding speed, the wire filling path and the layer thickness, etc., and realize the low heat input CMT arc additive manufacturing of pulsed welding wire transportation. The harmonic ultrasonic impact control device can precisely control the large-area overlap of the ultrasonic impact head 16 to strengthen the feed path and overlap rate, and at the same time, by regulating the output voltage and current of the harmonic vibration controller 10, different waveforms, frequencies and frequencies can be achieved. The ultrasonic impact method of amplitude can realize fast switching of different parameters for different materials. Among them, when forming high melting point and easily oxidized metal materials such as titanium alloys, the accompanying argon cannot meet the protection requirements, and a simple inert gas protection chamber needs to be installed. Among them, the harmonic ultrasonic shock control device needs to be connected with a waveform generator box during processing, which is the prior art and is used to generate high load and ultrasonic shock signals.

[0027] like image 3 Shown is the intention of the interlayer ultrasonic impact feeding strategy of the present invention, the overlap ratio of the ultrasonic impact strengthening treatment is 50% to achieve the effect of uniform strengthening; at the same time, ensure that the ultrasonic impact path is perpendicular to the filling wire path, in order to achieve more dense strengthening effect. In order to avoid the impact-strengthening layers on both sides being removed after the material reduction process to further improve the precision, we perform integrated ultrasonic impact strengthening after milling and flattening the side walls to achieve the effect of integrated toughness.

[0028] like Figure 4 It is a schematic diagram of the control effect mechanism of the coarse columnar crystals of the present invention. The surface ultrasonic impact can effectively refine the top grains, while the high overlap rate interlayer ultrasonic impact can better adjust the bonding interface state and block the growth of the coarse columnar crystals in the additive direction. growth, thereby effectively improving the anisotropy of the additive parts.

[0029] Figure 5It is a microstructure comparison diagram of the actual coarse columnar crystal regulation effect of the present invention. By comparison, it can be seen that the ultrasonic impact on the single-channel surface can effectively refine the top grains, while the high-lap rate interlayer ultrasonic impact can better adjust the bonding interface state and block the growth of coarse columnar crystals in the additive direction. Effectively improve the anisotropy of additive parts.

[0030] Using the method of interlayer ultrasonic impact assisted high-performance CMT arc additive manufacturing of the above device, after the cold metal transition arc additive control device completes the forming of a layer of material, the temperature sensor monitors the temperature of the interface of the deposited layer in real time. When the surface temperature drops to 200°C, the harmonic ultrasonic impact control device performs ultrasonic impact strengthening on the layer of material with a large area of ​​overlap, and the above steps are repeated until the workpiece is completely formed.

[0031] The following examples illustrate: the embodiment specifically includes the following steps:

[0032] The CMT arc additive manufacturing method using MIG/MAG welding, the welding wire used is 6063 aluminum alloy arc additive wire, and its diameter is 1.2mm; the substrate 18 is a 10mm thick 6063 aluminum alloy substrate;

[0033] Step S1: grinding the surface of the 6063 aluminum alloy substrate to remove the oxide layer, degreasing and cleaning with ethanol, then fixing it on the working platform 19, and preheating the substrate 18 by electrifying;

[0034] Step S2: the automatic wire feeding equipment sends the 6063 aluminum alloy arc additive wire into the wire preheating box 7 through the wire feeding pipeline 8 for preliminary preheating;

[0035] Step S3: The CMT arc additive equipment is turned on, the welding torch 1 is powered on, and its key parameters are set as follows: the peak current is 130A, the feeding speed of the welding torch is 0.3m/min, the wire feeding speed is 7.2m/min, the average voltage is 13V, Argon is used as protective gas, and the gas flow rate is 20L/min. After printing one layer, stop wire feeding and turn off the power;

[0036] Step S4: After the CMT arc additive equipment completes the deposition and forming of a certain number of layers on the substrate, the temperature sensor monitors the temperature of the interface of the deposited layer and drops to 200°C, and the harmonic ultrasonic impact control device starts to carry out large-area inspection of the interface material of the layer. Ultrasonic impact strengthening of lap joints: set the key parameters as follows: the operating frequency is 30kHz, the rated power is 1000W, the output amplitude is 50μm, the feed speed is 0.3m/min, the diameter of the impact head is 3mm, and the applied load is 25kN;

[0037] Step S5: Repeat steps S3 and S4 until the workpiece is completely formed;

[0038] Step S6: After milling the corrugated protrusions on the two sides of the formed 6063 aluminum alloy straight wall, use a harmonic ultrasonic impact system to perform ultrasonic impact processing on the side walls to achieve the effect of overall strengthening.

[0039] The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.