Method for magnetohydrodynamic (MHD) printhead/nozzle reuse

1. A method for operating a printer, comprising:

draining a print material from a supply reservoir of the printer, wherein the print material is a first metal having a first melting point;

placing a sacrificial metal into the supply reservoir of the printer, wherein the sacrificial metal is a second metal having a second melting point that is lower than the first melting point;

ejecting the sacrificial metal from a nozzle of the printer; and

cooling the printer subsequent to ejecting the sacrificial metal from the nozzle.

2. The method of claim 1 , further comprising ejecting the print material from the nozzle of the printer prior to the draining of the print material.

3. The method of claim 2 , wherein the ejecting of the print material further comprises ejecting the first metal from the nozzle at a temperature that is above the first melting point.

4. The method of claim 3 , further comprising ejecting the print material from the nozzle of the printer when the print material is at a temperature of from 600° C. to 2000° C.

5. The method of claim 1 , wherein:

the first metal comprises aluminum and has a melting point greater than 600° C.;

the draining of the print material comprises ejecting the print material from the nozzle of the printer at a temperature greater than 600° C.;

the second metal comprises tin and has a melting point less than 300° C.; and

the ejecting of the sacrificial metal from the nozzle comprises ejecting the sacrificial metal from the nozzle of the printer at a temperature of less than 300° C.; and

the cooling of the printer comprises cooling the sacrificial metal to a temperature of from 20° C. to 22° C.

6. The method of claim 1 , further comprising:

placing a volume of the print material within the supply reservoir of the printer subsequent to the cooling of the printer; then

ejecting the print material from the nozzle of the printer at a temperature above the first melting point.

7. A printer shutdown process, comprising:

draining a metal print material from a supply reservoir of the printer, wherein the print material has a first melting point and the metal print material is at a first temperature that is above the first melting point during the draining;

placing a sacrificial metal within the supply reservoir of the printer;

ejecting the sacrificial metal from the supply reservoir of the printer through a nozzle of the printer, wherein the sacrificial metal has a second melting point that is lower than the first melting point and the sacrificial metal is at a second temperature that is below the first melting point and above the second melting point during the ejecting; and

cooling the printer to a third temperature that is below the first melting point of the print material and the second melting point of the sacrificial metal.

8. The printer shutdown process of claim 7 , wherein:

the first temperature is from 600° C. to 2000° C.; and

the second temperature is below 300° C.

9. The printer shutdown process of claim 8 , wherein:

the print material comprises from 80% to 100% aluminum; and

the sacrificial metal comprises from 30% to 100% tin.

10. The printer shutdown process of claim 8 , wherein the sacrificial metal comprises from 20% to 100% of gallium, indium, tin, bismuth, zinc, cadmium, or lead, or combinations of two or more thereof.

11. A method for operating a printer, comprising:

ejecting a metal print material at a temperature of from 600° C. to 2000° C. from a nozzle of a printer;

draining the metal print material at a temperature of from 600° C. to 2000° C. from the printer subsequent to the ejecting;

placing a sacrificial metal into a supply reservoir of the printer;

heating the sacrificial metal to a temperature of 300° or less, thereby melting the sacrificial metal;

ejecting the sacrificial metal from the nozzle of the printer while the sacrificial metal is melted and at a temperature of 300° C. or less; and

cooling the printer to a temperature of from 20° C. to 22° C. subsequent to the ejecting of the sacrificial metal from the nozzle of the printer, thereby solidifying the sacrificial metal within the printer.

12. The method of claim 11 , further comprising:

subsequent to the cooling of the printer, heating the sacrificial metal within the printer to a temperature of 300° C. or less, thereby melting the sacrificial metal;

draining the melted sacrificial metal from the printer;

placing the metal print material into the supply reservoir of the printer;

heating the metal print material to a temperature of from 600° C. to 2000° C., thereby melting the metal print material; then

ejecting the metal print material at a temperature of from 600° C. to 2000° C. from the nozzle of the printer.

13. The method of claim 11 , further comprising:

placing the drained metal print material into the supply reservoir of the printer;

heating the drained metal print material to a temperature of from 600° C. to 2000° C., thereby melting the drained metal print material; and

ejecting the melted drained metal print material from the nozzle of the printer.

14. The method of claim 11 , wherein the metal print material comprises at least one of aluminum, copper, iron, and titanium, or combinations of two or more thereof.

15. The method of claim 11 , wherein the sacrificial metal comprises at least one of gallium, indium, tin, bismuth, zinc, cadmium, or lead, or combinations of two or more thereof.

16. The method of claim 11 , wherein:

the metal print material comprises at least one of aluminum, copper, iron, and titanium, or combinations thereof; and

the sacrificial metal comprises at least one of gallium, indium, tin, bismuth, zinc, cadmium and lead or combinations of two or more thereof, and further comprises at least one of aluminum, copper, iron, and titanium, or combinations of two or more thereof.