Aluminum-scandium composite, aluminum-scandium composite sputtering target and methods of making
An Al—Sc alloy sputtering target. The target comprising from 1.0 at % to 65 at % scandium and from 35 at % to 99 at % aluminum and having a microstructure including a first aluminum matrix phase and a second phase dispersed uniformly therethrough. The second phase comprises one or more compounds corresponding to the formula Sc x Al y , where x is from 1 to 2 and y is from 0 to 3.
1 . An Al—Sc composite comprising from 1.0 at % to 65 at % scandium (Sc) and from 35 at % to 99 at % aluminum (Al), having a microstructure including a first aluminum matrix phase and a second phase dispersed therethrough, the second phase comprising a compound corresponding to the formula Al x Sc y , where x is from 0 to 3 and y is from 1 to 2; wherein the concentration of scandium in the second phase is at least 1% greater than the concentration predicted by the equilibrium phase diagram for aluminum-scandium.
2 . The composite of claim 1 , wherein the second phase comprises Al 3 Sc, Al 2 Sc, AlSc, AlSc 2 , Sc, or combinations thereof.
3 . The composite of claim 1 , wherein the second phase comprises less than 60 mol % Al 2 Sc, based on the total moles of the second phase.
4 . The composite of claim 1 , wherein the composite comprises at least 5 vol % of the first aluminum matrix phase as determined by quantitative image analysis.
5 . The composite of claim 1 , wherein the microstructure includes from 20 vol % to 99 vol % of the first aluminum matrix phase and from 1% to 80 vol % of the second phase as determined by quantitative image analysis.
6 . The composite of claim 1 , wherein the concentration of scandium in the second phase is greater than the concentration predicted by the equilibrium phase diagram for aluminum-scandium.
7 . The composite of claim 1 , wherein the second phase comprises greater than 25 at % scandium.
8 . The composite of claim 1 , wherein the second phase comprises greater than 1 mol % of Al 2 Sc, AlSc, AlSc 2 , or Sc or combinations thereof.
9 . The composite of claim 1 , wherein the second phase comprises less than 85 mol % aluminum.
10 . The composite of claim 1 , wherein the second phase further comprises from 1.0 mol % to 70 mol % scandium nitride (ScN).
11 . The composite of claim 1 , wherein grains of the first aluminum matrix phase are characterized by a crystallographic orientation of (110).
12 . The composite of claim 1 , wherein grains of the first aluminum matrix phase are characterized by a random crystallographic orientation.
13 . The composite of claim 1 , wherein the second phase is characterized as having a particle size ranging from 0.5 microns to 500 microns.
14 . The composite of claim 1 , wherein the microstructure is substantially devoid of microcracks, fissures, and oxide inclusions.
15 . The composite of claim 1 , wherein the composite is a sputtering target comprising less than 1000 ppm of oxygen.
16 . A process for producing a non-equilibrium composite, as recited in claim 1 the process comprising:
providing a second phase powder comprising a compound corresponding to the formula Al x Sc y , where x is from 0 to 3 and y is from 1 to 2;
mixing the powder with a first phase comprising aluminum to form a composite precursor;
applying at least one of heat or pressure to the composite precursor to consolidate the materials; and
cooling the consolidated composite precursor to form the non-equilibrium composite;
wherein the concentration of scandium in the second phase is at least 1% greater than the concentration predicted by the equilibrium phase diagram for aluminum-scandium.
17 . The process of claim 16 , wherein the compound comprises Al 3 Sc, Al 2 Sc, AlSc, AlSC 2 , Sc, or combinations thereof, present in an amount greater than 1 mol %, and free aluminum, present in an amount greater than 20 vol %.
18 . An Al—Sc composite sputtering target comprising from 1.0 at % to 65 at % scandium (Sc) and from 35 at % to 99 at % aluminum (Al), having a microstructure including a first aluminum matrix phase and a second phase dispersed therethrough, the second phase comprising a compound corresponding to the formula Al x Sc y , where x is from 0 to 3 and y is from 1 to 2; wherein the concentration of scandium in the second phase is at least 1% greater than the concentration predicted by the equilibrium phase diagram for aluminum-scandium.
19 . The sputtering target of claim 18 , wherein the uniformity of scandium across a surface of the sputtering target varies by less than +/−0.5 at % scandium over an entire radius of the surface.
20 . An Al—Sc composite comprising from 1.0 at % to 65 at % scandium (Sc) and from 35 at % to 99 at % aluminum (Al), having a microstructure including a first aluminum matrix phase and a second phase dispersed therethrough, the second phase comprising a compound corresponding to the formula Al x SC y , where x is from 0 to 3 and y is from 1 to 2, wherein the second phase further comprises from 1.0 mol % to 70 mol % scandium nitride (ScN).
21 . A process for producing a non-equilibrium composite, as recited in claim 20 the process comprising:
providing a second phase powder comprising a compound corresponding to the formula Al x Sc y , where x is from 0 to 3 and y is from 1 to 2;
mixing the powder with a first phase comprising aluminum to form a composite precursor;
applying at least one of heat or pressure to the composite precursor to consolidate the materials; and
cooling the consolidated composite precursor to form the non-equilibrium composite;
wherein the second phase further comprises from 1.0 mol % to 70 mol % scandium nitride (ScN).
22 . An Al—Sc composite sputtering target comprising from 1.0 at % to 65 at % scandium (Sc) and from 35 at % to 99 at % aluminum (Al), having a microstructure including a first aluminum matrix phase and a second phase dispersed therethrough, the second phase comprising a compound corresponding to the formula Al x Sc y , where x is from 0 to 3 and y is from 1 to 2; wherein the second phase further comprises from 1.0 mol % to 70 mol % scandium nitride (ScN).