Multi step processing method for the fabrication of complex articles made of metallic glasses

Patent metadata

Field	Value
Publication number	US-10047420-B2
Application number	US-201314385349-A
Country	US
Kind code	B2
Filing date	Mar 15, 2013
Priority date	Mar 16, 2012
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

In one embodiment, the invention provides a process for thermoplastic forming of a metallic glass. For example, in one embodiment, the invention provides a process for thermoplastic forming of a metallic glass ribbons having a thickness of between about 50 to about 200 microns. Related articles of manufacture and processes for customizing articles in accordance with the process as described herein are also provided.

First claim

What is claimed is:

1. A process for thermoplastic forming of a metallic glass, the process comprising the steps of:
(a) providing an amorphous metallic glass feedstock, the feedstock comprising Pd 43 Ni 10 Cu 27 P 20 ;
(b) heating the feedstock at a first temperature which is equal to or greater than the glass transition temperature of the feedstock so that the feedstock is in a supercooled liquid state, thereby enabling a homogeneous first deformation treatment of the feedstock;
(c) discontinuing heating of the feedstock while the crystallized volume fraction of the feedstock is less than a predetermined crystallized volume fraction; and
(d) after a predetermined interval during which cooling of the feedstock occurs, reheating the feedstock at a second temperature so that the feedstock is in a supercooled liquid state, thereby enabling a homogeneous second deformation treatment of the feedstock; and
(e) discontinuing reheating of the feedstock while the total crystallized volume fraction of the feedstock is less than said predetermined crystallized volume fraction.

2. The process of claim 1 , further comprising subjecting the feedstock to the first deformation treatment during the heating of the feedstock, wherein the first deformation treatment is under conditions of temperature and strain rate that result in homogenous deformation, also comprising discontinuing the first deformation treatment while the crystallized volume fraction of the feedstock is less than said predetermined crystallized volume fraction.

3. The process of claim 1 wherein a minimal detectable crystallized volume fraction is between about 1% and about 10% of total feedstock volume.

4. The process of claim 1 , further comprising quenching the feedstock or subjecting the feedstock to controlled cooling; and optionally annealing the feedstock.

5. The process of claim 1 wherein the heating and reheating of the feedstock are at approximately uniform temperatures.

6. The process of claim 1 wherein the heating and reheating of the feedstock occur for respective time periods, the first temperature and the second temperature being the same approximately uniform temperature over said time periods.

7. The process of claim 1 wherein the feedstock is heated in at least one of step (b) and (d) at an increasing temperature over two or more discrete time periods.

8. The process of claim 1 further comprising using x-ray diffraction or thermal analysis to determine the crystallized volume fraction of the feedstock during the heating and reheating of the feedstock.

9. The process of claim 1 wherein said predetermined crystallized volume fraction is a minimum detectable crystallized volume fraction.

10. The process of claim 1 further comprising subjecting the workpiece to a treatment process during the discontinuing of the heating of the feedstock, while the feedstock is maintained at a temperature less than the glass transition temperature, said treatment process being taken from the group consisting of quenching, controlled cooling, annealing and combinations thereof.

11. A process for the customization of an article comprised of an amorphous metallic glass, the process comprising subjecting the article to the process of claim 1 wherein the article serves as the amorphous metallic glass feedstock and wherein subsequent to the discontinuing of the reheating of the feedstock, feedstock dimensions are compared to at least one reference value and the feedstock undergoes steps (a)-(e) of claim 1 until differences between the feedstock dimensions and at least one reference value fall within a tolerance range.

12. The process of claim 1 , further comprising repeating steps (d) and (e) at least one more time to enable deforming of the feedstock into a final predetermined geometry while maintaining the total crystallized volume fraction of the feedstock lower than the predetermined crystallized volume fraction.

13. The process of claim 1 , further comprising subjecting the feedstock to the second-deformation treatment during the reheating of the feedstock, wherein the second deformation treatment is under conditions of temperature and strain rate that result in homogenous deformation, also comprising discontinuing the second deformation treatment while the crystallized volume fraction of the feedstock is less than said predetermined crystallized volume fraction.

14. A process for thermoplastic forming of metallic glass ribbons, the process comprising the steps of:
(a) providing an amorphous metallic glass feedstock;
(b) homogeneously treating the feedstock by heating the feedstock at a temperature which is equal to or greater than the glass transition temperature of the feedstock;
(c) discontinuing heating of the feedstock when the feedstock has a crystallized volume fraction of less than a predetermined value;
(d) after a predetermined interval, reheating the feedstock at a second temperature which is equal to or greater than the glass transition temperature of the feedstock so that the feedstock is in a supercooled liquid state, thereby enabling homogeneous deforming of the feedstock;
(e) during the reheating of the feedstock, while the feedstock is at said second temperature, subjecting the feedstock to homogeneous deformation in the form of rolling the feedstock into ribbons;
(f) either quenching the feedstock or subjecting the feedstock to controlled cooling; and
(g) optionally annealing the feedstock, wherein during the heating and reheating of the feedstock, the feedstock exists as a supercooled liquid enabling homogenous deformation of the feedstock, and wherein the total crystallized volume fraction of the feedstock after the heating and reheating of the feedstock is lower than a preselected crystallized volume fraction.

15. The process of claim 14 , wherein the feedstock is heated in step (b) at an approximately uniform temperature.

16. The process of claim 15 , wherein the feedstock is heated in step (b) at an incrementally increasing temperature.

17. The process of claim 14 , wherein the feedstock is heated in step (b) at an approximately uniform temperature over two or more discrete time periods.

18. The process of claim 14 , wherein the feedstock is heated in step (b) at an incrementally increasing temperature over two or more discrete time periods.

19. The process of claim 14 , wherein the metallic glass ribbon is adaptable for use as a main spring for a mechanical watch movement.

20. The process of claim 14 , wherein subsequent to the step of rolling the feedstock to form ribbons, the ribbons are reheated and a scraping process is applied to the ribbons to remove excess material.

21. The process of claim 14 , wherein: (1) subsequent to the step of homogeneously deforming the feedstock by heating the feedstock at a temperature which is equal to or greater than the glass transition temperature of the feedstock; and (2) prior to the step of discontinuing heating of the feedstock, the homogeneously deformed feedstock is subjected to one or more addition process steps selected from the group consisting of grinding, polishing, and elastic or plastic deformation.

Assignees

• Univ Yale

Inventors

• Schroers Jan
• Hodges Thomas M
• Kanik Michael
• Bordeenithikasem Punnathat

Classifications

• C22C1/11

  Making amorphous alloys · CPC title

• C21D7/13

  by hot working · CPC title

• C22F1/002

  by rapid cooling or quenching; cooling agents used therefor · CPC title

• C22F1/00

  Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working (apparatus for mechanical working of metal B21, B23, B24) · CPC title

• C22C45/00 Primary

  Amorphous alloys (making amorphous non-ferrous alloys C22C1/11) · CPC title