Systems and methods for implementing bulk metallic glass-based macroscale compliant mechanisms

Patent metadata

Field	Value
Publication number	US-9783877-B2
Application number	US-201313942932-A
Country	US
Kind code	B2
Filing date	Jul 16, 2013
Priority date	Jul 17, 2012
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

Systems and methods in accordance with embodiments of the invention implement bulk metallic glass-based macroscale compliant mechanisms. In one embodiment, a bulk metallic glass-based macroscale compliant mechanism includes: a flexible member that is strained during the normal operation of the compliant mechanism; where the flexible member has a thickness of 0.5 mm; where the flexible member comprises a bulk metallic glass-based material; and where the bulk metallic glass-based material can survive a fatigue test that includes 1000 cycles under a bending loading mode at an applied stress to ultimate strength ratio of 0.25.

First claim

What claimed is:

1. A macroscale compliant mechanism comprising:
a flexible member that is strained during the operation of the compliant mechanism;
wherein the flexible member has a thickness of at least approximately 0.5 mm;
wherein the flexible member comprises a bulk metallic glass-based material; and
wherein the bulk metallic glass-based material can survive a fatigue test that includes 1000 cycles under a bending loading mode at an applied stress to ultimate strength ratio of 0.25; and

wherein the flexible member is configured such that its displacement-response to an applied force is nonlinear;
wherein the bulk metallic glass-based material is a bulk metallic glass matrix composite;
wherein the compliant mechanism is selected from the group consisting of a cutting device, a grasping device, a bistable mechanism, and a rotational hexfoil flexure; and
wherein the cutting device comprises:
a bladed section with a first and second blade; and
a handled section with a first and second handle;
wherein the cutting device is configured such that the rotation of the handles towards one another causes the rotation of the blades towards one another;

wherein the grasping device comprises:
a grasping section with a first and second grasping element; and
a handled section with a first and second handle;
wherein the grasping device is configured such that the rotation of the handles towards one another causes the rotation of the grasping elements towards one another;

wherein the bistable mechanism is configured to be stable in two configurations; and
wherein the rotational hexfoil flexure comprises:
a base cylindrical portion;
an overlaid cylindrical portion; and
three beams;
wherein one end of each beam is adjoined to the base cylindrical portion, and the opposite end of each beam is adjoined to the overlaid cylindrical portion;
wherein the rotational hexfoil flexure is configured such that the base cylindrical portion and the overlaid cylindrical portion can be rotated relative to one another.

2. The bulk metallic glass-based macroscale compliant mechanism of claim 1 , wherein the volume fraction of crystals within the bulk metallic glass matrix composite is between approximately 20% and 80%.

3. The bulk metallic glass-based macroscale compliant mechanism of claim 1 , wherein the bulk metallic glass-based material has a yield strain greater than approximately 1.5%.

4. The bulk metallic glass-based macroscale compliant mechanism of claim 2 , wherein the bulk metallic glass-based material has a strength to stiffness ratio greater than approximately 2.

5. The bulk metallic glass-based macroscale compliant mechanism of claim 1 , wherein the bulk metallic glass-based material is one of: Ti 44.3 Zr 20 V 12 Cu 5 Be 15 , Zr 39.6 Ti 33.9 Nb 7.6 Cu 6.4 Be 12.5 , Zr 56.2 Ti 13.8 Nb 5.0 Cu 6.9 Be 12.5 , Ti 31.4 Zr 36.6 Nb 7 Cu 5.9 Be 19.1 , Ti 43 Zr 25 Nb 7 Cu 6 Be 19 , and Ti 25 Zr 43 Nb 7 Cu 6 Be 19 .

6. The bulk metallic glass-based macroscale compliant mechanism of claim 1 , wherein the bulk metallic glass-based macroscale compliant mechanism is a TiZrBeXY alloy, wherein X is an additive that enhances glass forming ability and Y is an additive that enhances toughness.

7. The bulk metallic glass-based macroscale compliant mechanism of claim 6 , wherein the bulk metallic glass-based material comprises:
Ti in an amount between approximately 10 and 60 atomic %;
Zr in an amount between approximately 18 and 60 atomic %; and
Be in an amount between approximately 7 and 30 atomic %.

8. The bulk metallic glass-based macroscale compliant mechanism of claim 7 , wherein X is one of Fe, Cr, Co, Ni, Cu, Al, B, C, Ag, Si, and mixtures thereof.

9. The bulk metallic glass-based macroscale compliant mechanism of claim 7 , wherein:
X is one of: C, Si, and B; and
X is present in an amount less than approximately 2 atomic %.

10. The bulk metallic glass-based macroscale compliant mechanism of claim 7 , wherein:
X is one of: Cr, Co, and Fe; and
X is present in an amount less than approximately 7 atomic %.

11. The bulk metallic glass-based macroscale compliant mechanism of claim 7 , wherein X is Al and is present in an amount less than approximately 7 atomic %.

12. The bulk metallic glass-based macroscale compliant mechanism of claim 7 , wherein X is a combination of Cu and Ni, and is present in an amount less than approximately 20 atomic %.

13. The bulk metallic glass-based macroscale compliant mechanism of claim 7 , wherein the combination of X and Be is present in an amount less than approximately 30 atomic %.

14. The bulk metallic glass-based macroscale compliant mechanism of claim 13 , wherein Y is one of: V, Nb, Ta, Mo, Sn, W, and mixtures thereof.

15. The bulk metallic glass-based macroscale compliant mechanism of claim 14 , wherein Y is V and is present in amount less than approximately 15 atomic %.

16. The bulk metallic glass-based macroscale compliant mechanism of claim 14 , wherein Y is Nb and is present in an amount between approximately 5 and 15 atomic %.

17. The bulk metallic glass-based macroscale compliant mechanism of claim 14 , wherein Y is Ta and is present in an amount less than approximately 10 atomic %.

18. The bulk metallic glass-based macroscale compliant mechanism of claim 14 , wherein Y is Mo and is present in an amount less than approximately 5 atomic %.

19. The bulk metallic glass-based macroscale compliant mechanism of claim 14 , wherein Y is Sn and is present in an amount less than approximately 2 atomic %.

20. The bulk metallic glass-based macroscale compliant mechanism of claim 1 , wherein the bulk metallic glass-based material can survive a fatigue test that includes 1000 cycles under a bending loading mode at an applied stress to ultimate strength ratio of 0.4.

21. A bulk metallic glass-based macroscale compliant mechanism comprising:
a flexible member that is strained during the normal operation of the compliant mechanism;
wherein the flexible member has a thickness of 0.5 mm;
wherein the flexible member comprises a bulk metallic glass-based material; and
wherein the bulk metallic glass-based material can survive a fatigue test that includes 1000 cycles under a bending loading mode at an applied stress to ultimate strength ratio of 0.25;

wherein the compliant mechanism is a cutting device comprising:
a bladed section with a first and second blade; and
a handled section with a first and second handle;
wherein the cutting device is configured such that the rotation of the handles towards one another causes the rotation of the blades towards one another.

22. A bulk metallic glass-based macroscale compliant mechanism comprising:
a flexible member that is strained during the normal operation of the compliant mechanism;
wherein the flexible member has a thickness of 0.5 mm;
wherein the flexible member comprises a bulk metallic glass-based material; and
wherein the bulk metallic glass-based material can survive a fatigue test that includes 1000 cycles under a bending loading mode at an applied stress to ultimate strength ratio of 0.25;

wherein the compliant mechanism is a grasping device comprising:
a grasping section with a first and second grasping element; and
a handled section with a first and second handle;
wherein the grasping device is configured such that the rotation of the handles towards one another causes the rotation of the grasping elements towards one another.

23. A bulk metalli

Assignees

• California Inst Of Techn

Inventors

• Hofmann Douglas C
• Agnes Gregory

Classifications

• B21J5/027

  Trimming · CPC title

• C22C45/00 Primary

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

• C22C45/10

  with molybdenum, tungsten, niobium, tantalum, titanium, or zirconium {or Hf} as the major constituent · CPC title

• C22C45/06

  with beryllium as the major constituent · CPC title

• C22C1/11

  Making amorphous alloys · CPC title