Method of Rapidly Melting Metal for 3D Metal Printers by Electromagnetic Induction

Abstract

This invention relates to the field of 3D metal printing, and more particularly to a method of rapidly melting metal for 3D metal printers by electromagnetic induction. This is a new cost-effective 3D metal printing method that enables direct heating and rapid melting of metals, higher energy conversion efficiency, higher deposition rates, smaller oxide, higher safety and controllability, faster printing, and larger-size metal components manufacturing.

Claims

1. A method of rapidly melting metal for 3D metal printers by electromagnetic induction, comprising a nozzle (R), a crucible (C), a middle-high frequency inverter power supply (P), an electromagnetic induction coil (B), a cooling device (D) and metal to be melted (M), the electromagnetic induction coil (B) surrounds the crucible (C), the cooling device (D) cools the electromagnetic induction coil (B), the middle-high frequency inverter power supply (P) drives the electromagnetic induction coil (B) to rapidly melt the metal to be melted (M) in the crucible (C) due to electromagnetic induction to form fluid or liquid of metal (L), the fluid or liquid of metal (L) is ejected through the nozzle (R).

2. The method of rapidly melting metal for 3D metal printers by electromagnetic induction according to claim 1, wherein the output signal of the middle-high frequency inverter power supply (P) is a sine wave with frequency from 200 Hz to 2 MHz.

3. The method of rapidly melting metal for 3D metal printers by electromagnetic induction according to claim 1, wherein the output signal of the middle-high frequency inverter power supply (P) is a square wave with frequency from 200 Hz to 2 MHz.

4. The method of rapidly melting metal for 3D metal printers by electromagnetic induction according to claim 1, wherein the cooling device (D) is in a water-cooling manner.

5. The method of rapidly melting metal for 3D metal printers by electromagnetic induction according to claim 1, wherein the cooling device (D) is in an air-cooling manner.

6. The method of rapidly melting metal for 3D metal printers by electromagnetic induction according to claim 1, wherein the cooling device (D) is in a semiconductor cooling manner.

7. The method of rapidly melting metal for 3D metal printers by electromagnetic induction according to claim 1, wherein the electromagnetic induction coil (B) is made of a hollow metal pipe that is injected circulating water for cooling through the cooling device (D).

8. The method of rapidly melting metal for 3D metal printers by electromagnetic induction according to claim 1, wherein the crucible (C) is made of non-electromagnetic induction material.

9. The method of rapidly melting metal for 3D metal printers by electromagnetic induction according to claim 1, wherein the crucible (C) is made of electromagnetic induction material.

10. The method of rapidly melting metal for 3D metal printers by electromagnetic induction according to claim 1, wherein a thermal insulation layer is used between the crucible (C) and the electromagnetic induction coil (B) for thermal isolation when the crucible (C) is made of electromagnetic induction material.

11. The method of rapidly melting metal for 3D metal printers by electromagnetic induction according to claim 1, wherein a thermal insulation layer is used between the crucible (C) and the electromagnetic induction coil (B) for thermal isolation when the crucible (C) is made of non-electromagnetic induction material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 is an overall structure diagram of the present invention, which represents the method of the rapidly melting metal for 3D metal printers by electromagnetic induction.

[0019] FIG. 2 is a block diagram showing a basic circuit connection of an embodiment of the present invention.

[0020] FIG. 3 is a schematic of an embodiment of the present invention.

[0021] In the figures, R: nozzle, C: crucible, B: electromagnetic induction coil, P: middle-high frequency inverter power supply, D: cooling device, M: metal to be melted, L: fluid or liquid of metal, +V: operating voltage for middle-high frequency inverter power supply, C1: capacitor, L1&L2: inductors, Q1&Q2: field effect transistors, D1-D4: diodes, R1-R4: resistors.

DETAILED DESCRIPTION OF THE EMBODIMENT

[0022] For a better understanding of the invention, an embodiment of the present invention will be described in detail hereinafter in conjunction with the drawings.

[0023] As shown in FIG. 1, the method of rapidly melting metal for 3D metal printers by electromagnetic induction comprises a nozzle (R), a crucible (C), a middle-high frequency inverter power supply (P), an electromagnetic induction coil (B), a cooling device (D), and metal to be melted (M). The electromagnetic induction coil (B) surrounds the crucible (C), and the cooling device (D) cools the electromagnetic induction coil (B). The middle-high frequency inverter power supply (P) drives the electromagnetic induction coil (B) by high current middle-high frequency (200 Hz to 2 MHz) sine wave or square wave signal, a high density magnetic field line is generated in the electromagnetic induction coil (B) and produces a large eddy current in the metal (M) in the crucible (C), so the metal (M) in the crucible (C) is rapidly melted due to such electromagnetic induction, and turns into the fluid or liquid of metal (L). The fluid or liquid of metal (L) is ejected through the nozzle (R). The ejection methods can be achieved in some mature ways, such as piezoelectric, pneumatic, electric piston type (Wang Yun Gang et Al. 3D Printing Technology, Huazhong University of Science and Technology Press, China), which will not be repeated here.

[0024] FIG. 2 shows the block diagram of the basic circuit connection of the embodiment of the present invention: the middle-high frequency inverter power supply (P) is connected to the electromagnetic induction coil (B).

[0025] In the schematic of the embodiment shown in FIG. 3, two field effect transistors Q1, Q2 and its peripheral components (C1, B, L1, L2, D1-D4, R1-R4) make up a standard LC resonant selection frequency oscillation circuit, the resonant frequency f0=1/(2{square root over (BC1)}), where the frequency range is from 200 Hz to 2 MHz. +V provides the power supply to the entire oscillation circuit, and B is not only the inductance of the LC resonant circuit, but also the electromagnetic induction coil. B is around the crucible (C), heats the metal (M) in the crucible (C) through electromagnetic induction, and then melts the metal (M) rapidly. The power output of the middle-high frequency inverter power supply (P) can be controlled easily by controlling the voltage of +V, so as to control the temperature and oxide rate of the fluid or liquid of metal (L) easily.

[0026] In summary, this invention can achieve cost-effective 3D metal printing which enables direct heating and rapid melting of metals, higher energy conversion efficiency, higher deposition rate, smaller oxide, higher safety and controllability, faster printing, and larger-size metal components manufacturing.