Injection device and method for producing at least one metallic glass part

Patent metadata

Field	Value
Publication number	US-11465198-B2
Application number	US-201816620418-A
Country	US
Kind code	B2
Filing date	Jun 4, 2018
Priority date	Jun 9, 2017
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

An injection device and method for producing at least one metallic glass part, in which a vertical piston is able to move in a vertical direction, a top end portion of the piston being suitable for being engaged in an injection chamber of a mould linked to a cavity of this mould and open at the bottom; the piston having a top end face on which an element made from metallic glass to be introduced into said chamber can be positioned, the top face of the piston having a concave shape suitable for receiving a bottom portion of the element made from metallic glass. A heating means situated under the mould comprises induction coils, such that, when the piston is in an intermediate position, the majority of the metallic element is situated in the space surrounded by the induction coils.

First claim

The invention claimed is:

1. An injection device for producing at least one metallic glass part, comprising:
a mold having at least one cavity and an injection chamber in connection with the at least one cavity, wherein the injection chamber has a lower injection opening extending through a lower surface of the mold and a sidewall surface extending upwardly from the injection opening;
a vertical injection piston coaxial with the injection chamber, the piston being arranged for vertical movement between a lower load position and an upper injection position;
the piston having an upper surface for retaining a charge volume of a metallic material, wherein when the piston is moved upwardly into the injection position, the metallic material is forced into an upper region of the injection chamber, thereby causing a first portion of the metallic material to be injected into the least one cavity;
wherein the upper surface of the piston comprises a recess for receiving and retaining a minor portion of the charge volume of the metallic material whereby a major portion of the charge volume of the metallic material extends above an uppermost portion of the upper surface of the piston; and

a heating element situated under the mold and coaxial with the piston, whereby, when the piston moves upwardly from an initial load position to an injection position, the charge volume of the metallic material will pass through and be directly exposed to the heating element before entering the injection chamber.

2. The device according to claim 1 , wherein the top surface of the piston further comprises a peripheral chamfered surface.

3. The device according to claim 2 , wherein a lower portion of the injection chamber defines a frustoconical surface.

4. The device according to claim 1 , wherein the recess defines a spherical cap, conical, arcuate, or frustoconical surface.

5. The device according to claim 1 , wherein the injection chamber comprises a lower entry portion having a first width and an upper chamber having a second width, wherein the first width is larger than the second width.

6. The device according to claim 1 , wherein an upper portion of the piston comprises an outer surface configured to establish a slide fit with the sidewall surface of the injection chamber.

7. The device according to claim 1 , further comprising:
a sleeve disposed around an upper portion of the piston and capable of sliding vertically relative to the piston, the piston and the sleeve having an axial abutment element that limits an upwards movement of the sleeve relative to the piston and a spring biasing the sleeve upwardly relative to the piston, wherein the sleeve comprises an annular bearing face configured for contacting an annular bearing face of the mold situated at a periphery of the injection opening.

8. The device according to claim 7 wherein the sleeve is able to slide vertically relative to the upper portion of the piston by forming a slide fit.

9. The device according to claim 7 , wherein the sleeve has an annular top surface situated approximately at the top end face of the piston when the abutment element are in abutment.

10. The device according to claim 7 , wherein the annular bearing face of the sleeve and the annular bearing face of the mold extend radially.

11. The device according to claim 7 , wherein the annular bearing face of the sleeve and the annular bearing face of the mold are frustoconical.

12. The device according to claim 7 , wherein a top portion of the sleeve is capable of entering an antechamber provided in of mold beneath and axially aligned with the injection chamber.

13. The device according to claim 1 , wherein the heating element is capable of putting the metallic material in fusion before the metal material enters the injection chamber.

14. The device according to claim 1 , further comprising a heating element provided at the upper of the vertical piston.

15. An injection method for producing at least one metallic glass part, comprising the steps of:
preparing an injection mold comprising an injection chamber with an injection opening through a lower surface of the mold and at least one cavity corresponding to the part in communication with the injection chamber;
placing a charge volume of a solid metallic element capable of forming a metallic glass on a top surface of a vertical injection piston, the top surface comprising a recess configured for receiving a minor portion of the charge volume with a major portion of the charge volume extending above the uppermost portion of the top surface;
heating the charge volume of said metallic element by passing the charge volume through an induction heater, the induction heater comprising an induction coil arranged to be directly coaxial to the piston, such that, when the piston is in an intermediate position, the majority of the metallic element is in an open space and surrounded solely by the induction coils;
continuing the heating step until the metallic element is in fusion and assumes a shape of an oblate spheroid retained by the recess;
displacing the piston upwards to transfer the metallic element in fusion into the injection chamber to reach an injection pressure inside the injection chamber of the mold and inject a volume of the molten metallic material into the at least one cavity of the mold linked to the injection chamber; and
cooling the first volume of the metallic material to obtain an amorphous solid within the at least one cavity.

16. The method according to claim 15 , wherein, in order to inject the metallic material in fusion, a top portion of the piston is inserted into the injection chamber, the top portion of the piston and the injection chamber jointly forming a slide fit.

17. The method according to claim 15 , wherein a sleeve is mounted on the top end portion of the piston, wherein the sleeve and the top portion of the piston form therebetween a slide fit for sliding and wherein the sleeve and the mold have annular bearing faces bearing against one another when the metallic material is injected.

18. The method according to claim 17 , wherein, in a final injection position, a peripheral end chamber of the piston is facing and remote from the inside edge of the interface between the annular bearing faces bearing against one another.

19. The method according to claim 15 , further comprising a step of heating the top portion of the vertical piston.

20. An injection device for producing at least one metallic glass part, comprising:
a mold having at least one cavity and an injection chamber in connection with the at least one cavity, wherein the injection chamber has a lower injection opening extending through a lower surface of the mold and a sidewall surface extending upwardly from the injection opening;
a vertical injection piston coaxial with the injection chamber, the piston being arranged for vertical movement between a lower load position and an upper injection position;
the piston having an upper surface for retaining a charge volume of a metallic material wherein when the piston is moved upwardly into the injection position, the metallic material is forced into an upper region of the injection chamber, thereby causing a first portion of the metallic material to be injected into the least one cavity;
wherein the upper surface of the piston comprises a recess for receiving and retaining a minor portion of the charge volume of the metallic material whereby a major portion of the charge volume of the metallic material extends above an uppermost port

Assignees

• Univ Grenoble Alpes
• Inst Polytechnique Grenoble

Inventors

• Gravier Sébastien
• Kapelski Georges

Classifications

• B22D25/06

  by its physical properties (B22D27/00 takes precedence) · CPC title

• B22D17/203

  Injection pistons (B22D17/2053 takes precedence; for plastics B29C45/53) · CPC title

• B22D17/04 Primary

  Plunger machines · CPC title

• B22D17/02

  Hot chamber machines, i.e. with heated press chamber in which metal is melted · CPC title

• B22D17/30 Primary

  Accessories for supplying molten metal, e.g. in rations (supplying molten metal in ration in general B22D39/00) · CPC title