Application Cases

Experiment Name: Research Experiment on Drop-On-Demand Metal Additive Manufacturing

Research Direction: Metal Additive Manufacturing

Experiment Content: Utilizing a piezoelectric-driven valve to move the nozzle axially back and forth, the molten metal inside the nozzle generates a pulsed pressure due to inertia, which leads to the ejection of molten droplets for additive manufacturing.

Testing Equipment: ATA-7030 high-voltage amplifier, signal generator, piezoelectric-driven valve, etc.

Experiment Process: The signal from the signal generator is transmitted through the ATA-7030 high-voltage amplifier to the piezoelectric-driven valve, which moves the nozzle axially back and forth. The molten metal inside the nozzle generates a pulsed pressure due to inertia, leading to the ejection of molten droplets. The droplets are then deposited and formed into shapes according to a predetermined program under the motion control system. This method can be used for both two-dimensional lattice and circuit formation as well as three-dimensional part additive manufacturing.

Test Results:

 

(1) The key to achieving droplet ejection using the water hammer effect lies in controlling the magnitude and direction of the nozzle's reciprocating acceleration. This regulates the inertial force acting on the molten metal, thereby controlling the droplet ejection. The nozzle is set to first accelerate and then decelerate, moving upward and then downward, creating pressure changes. The initial pressure inside the nozzle is negative, followed by positive pressure. A significant pressure pulse is generated during the sudden change in velocity, making droplet ejection possible.

(2) Both simulation and experimental results indicate that the pulsed pressure generated by the water hammer effect is the decisive factor affecting the behavior of molten droplet ejection. Insufficient pulsed pressure fails to produce droplets, while excessive pulsed pressure leads to the formation of satellite droplets. The results show that increasing the nozzle displacement, decreasing the orifice diameter, reducing the motion period, and increasing the liquid column height can all enhance the orifice pulsed pressure, thereby increasing the flight speed of the ejected droplets.

(3) The additive manufacturing capabilities of the proposed technology have been verified through various applications, including the fabrication of welding spheres with uniform size, precise lattice patterns, and the construction of 2D circuits and 3D structures. Parametric experimental results indicate that increasing the nozzle displacement can enhance the tensile strength of 3D-printed components. These experiments highlight the stability, precision, and significant potential of this technology to advance metal additive manufacturing.

Power Amplifier Recommendation: ATA-7030 High-Voltage Amplifier

Figure: Specifications of the ATA-7030 High-Voltage Amplifier