Silicon-rich alloys
AssigneeMassachusetts Institute of Technology
InventorsChristopher A. Schuh, David S. Fischer
Life of this patent
Estimating the term…
Abstract
Castable silicon-based compositions have enhanced toughness and related properties compared to silicon. The con-based compositions comprise silicon at a concentration greater than 50% by weight and one or more additional elements in structure comprising a cubic silicon phase and an additional phase which may impart toughness through mechanisms related to plastic flow or crack interaction with interfacial boundaries.
Claims56
An object formed by
- melting silicon and at least one element together to form a liquid having a silicon concentration greater than 50% silicon by weight;
- disposing the liquid in a mold;
- and
- cooling the liquid, thereby simultaneously forming cubic silicon and a silicide arranged in a eutectic aggregation, constituting at least 80% by volume of the object, in the mold.
3-5. (canceled)
A method of forming a cast object, comprising:
- melting silicon and at least one element together to form a liquid having a silicon concentration greater than 50% silicon by weight;
- disposing the liquid in a mold;
- and
- cooling the liquid, thereby simultaneously forming cubic silicon and a silicide arranged in a eutectic aggregation, constituting at least 80% by volume of the object, in the mold.
9-13. (canceled)
A composition of matter comprising:
- a phase of cubic silicon;
- and
- a phase comprising a first element other than silicon, arranged in a eutectic aggregation with the phase of cubic silicon, constituting 80% or more of the composition of matter by volume,
- wherein the composition of matter exhibits a rising R-curve and has a silicon concentration greater than 50% by weight.
16-17. (canceled)
The composition of matter 14 wherein the phase of cubic silicon and the phase comprising a first element other than silicon are arranged in an anomalous eutectic structure.
23-25. (canceled)
(canceled)
A composition of matter comprising:
- a phase of cubic silicon;
- and
- a first silicide phase comprising a first element other than silicon, arranged in a eutectic aggregation with the phase of cubic silicon constituting 80% or more of the composition of matter by volume, the eutectic aggregation having a characteristic spacing λ,
- wherein the composition of matter has a silicon concentration greater than 50% by weight, a thickness greater than 10λ, and a fracture toughness greater than 1.2 MPa m1/2.
29-42. (canceled)
49-51. (canceled)
54-57. (canceled)
60-63. (canceled)
66-67. (canceled)
(canceled)
A composition of matter comprising:
- a phase of cubic silicon;
- and
- a first silicide phase comprising a first element other than silicon, arranged with the phase of cubic silicon in a eutectic aggregation constituting 80% or more of the composition of matter by volume, the eutectic aggregation having a characteristic spacing λ,
- wherein the composition of matter has a silicon concentration greater than 50% by weight and a thickness greater than 100λ.
A composition of matter comprising:
- a phase of cubic silicon;
- and
- a first disilicide phase comprising a first element other than silicon, arranged with the phase of cubic silicon in a eutectic aggregation constituting 80% or more of the composition of matter by volume, the eutectic aggregation having a characteristic spacing λ,
- wherein the composition of matter has a silicon concentration greater than 50% by weight and a thickness greater than 10λ.
73-84. (canceled)
(canceled)
(canceled)
92-98. (canceled)
A composition of matter comprising:
- silicon at a concentration greater than about 50% by weight;
- vanadium;
- and
- chromium,
- at respective concentrations each within two atomic percent of respective concentrations of silicon, vanadium and chromium at a point on a curve joining a eutectic composition between silicon and vanadium disilicide and a eutectic composition between silicon and chromium disilicide, liquids lying on the curve undergoing eutectic solidification upon cooling, wherein the composition of matter exhibits a rising R-curve.
101-103. (canceled)
The composition of matter of claim 101 wherein the two-phase eutectic aggregation comprises tantalum or niobium.
Dependencies are inferred from the claim text.