ALUMINUM ALLOYS HAVING IRON, SILICON, VANADIUM AND COPPER, AND WITH A HIGH VOLUME OF CERAMIC PHASE THEREIN

Abstract

New aluminum alloys having iron, vanadium, silicon, and copper, and with a high volume of ceramic phase therein are disclosed. The new products may include from 3 to 12 wt. % Fe, from 0.1 to 3 wt. % V, from 0.1 to 3 wt. % Si, from 1.0 to 6 wt. % Cu, from 1 to 30 vol. % ceramic phase, the balance being aluminum and impurities. The ceramic phase may be homogenously distributed within the alloy matrix.

Claims

1. An aluminum alloy consisting essentially of: from 3 to 12 wt. % Fe; from 0.1 to 3 wt. % V; from 0.1 to 3 wt. % Si; from 1.0 to 6 wt. % Cu; and from 1.0 to 30 vol. % ceramic phase; the balance being aluminum and impurities.

2. An aluminum alloy body made from the aluminum alloy of claim 1, the aluminum alloy body having an alloy matrix and a ceramic phase, wherein the aluminum alloy body comprises a homogenous distribution of the ceramic phase within the alloy matrix.

3. The aluminum alloy body of claim 2, wherein the aluminum alloy body is in the form of an engine component for an aerospace vehicle.

4. The aluminum alloy body of claim 2, comprising from 5 to 35 vol. % AlFeVSi dispersoids.

5. The aluminum alloy body of claim 4, wherein the AlFeVSi dispersoids comprise at least some copper.

6. The aluminum alloy body of claim 2, comprising a cellular structure comprising iron and copper.

7. The aluminum alloy of claim 1, wherein the ceramic phase is selected from the group consisting of TiB.sub.2, TiC, and combinations thereof.

8. The aluminum alloy of claim 1, wherein the ceramic phase is TiB.sub.2.

9. A method of making an aluminum alloy body, comprising: (a) dispersing a powder comprising in a bed, wherein the powder consists essentially of: from 3 to 12 wt. % Fe; from 0.1 to 3 wt. % V; from 0.1 to 3 wt. % Si; from 1.0 to 6 wt. % Cu; from 1.0 to 30 vol. % ceramic phase; and the balance being aluminum (Al) and impurities; (b) selectively heating a portion of the powder to a temperature above the liquidus temperature of the particular aluminum alloy body to be formed; (c) forming a molten pool having the Fe, V, Si, Cu, Al, and ceramic phase; (d) cooling the molten pool at a cooling rate of at least 1000° C. per second; and (e) repeating steps (a)-(d) to form an additively manufactured aluminum alloy body.

10. The method of claim 9, comprising: completing the additively manufactured aluminum alloy body, thereby realizing a final aluminum alloy product; naturally aging the final aluminum alloy product; and after the natural aging, artificially aging the final aluminum alloy product.

11. The method of claim 10, comprising: after the naturally aging step, deforming the final aluminum alloy product by from 1 to 10%.

12. The method of claim 10, wherein the artificial aging comprises: heating the final aluminum alloy product at a temperature of from 125° C. to 300° C. and for a period of from 2 to 48 hours.

13. The method of claim 12, wherein the final aluminum alloy product is in the form of an engine component for an aerospace or automotive vehicle, wherein the method comprises: incorporating the engine component into the aerospace or automotive vehicle.

14. The method of claim 13, comprising: operating the aerospace or automotive vehicle.

15. The method of claim 13, wherein the final aluminum alloy product is a compressor wheel for a turbo charger.

16. The method of claim 13, wherein the final aluminum alloy product is a blade for a turbine.

17. The method of claim 13, wherein the final aluminum alloy product is a heat exchanger.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 is a schematic, cross-sectional view of an additively manufactured Al—Fe—Si—V—Cu-Ceramic Phase product (100) having a generally homogenous microstructure.

[0032] FIG. 2 is a schematic, cross-sectional views of an additively manufactured product produced from a single powder and having a first region (200) comprising an Al—Fe—Si—V—Cu alloy and a second region (300) comprising a ceramic phase.

[0033] FIGS. 3a-3f are schematic, cross-sectional views of additively manufactured products having a first region (400) and a second region (500) different than the first region, where the first region is produced via a metal powder and the second region is produced via a ceramic-metal powder or a ceramic powder.

[0034] FIG. 4 is a schematic, perspective view of an embodiment of an electron beam apparatus for use in producing additively manufactured aluminum alloy bodies.

[0035] FIGS. 5(A) and 5(B) are scanning electron images of the Al—Fe—V—Si—Cu alloy in the as-built condition; FIG. 5(A) shows a fine distribution of Al—Fe—V—Si dispersoids; FIG. 5(B) shows a cellular structure comprising Fe and Cu.

DETAILED DESCRIPTION

Example 1

[0036] An Al—Fe—V—Si—Cu ingot was used as feedstock and was subject to an inert gas atomization process to produce powder. The powder was then screened and blended for use in producing additively manufactured products. The products were additively manufactured via powder bed fusion (PBF) using an EOS M280 machine. Chemical analysis of the powder and the as-built components (final products) was conducted via inductively coupled plasma (ICP), the results of which are shown in Table 2, below (all values in weight percent).

TABLE-US-00002 TABLE 2 Compositions Item Fe V Si Cu Balance* Starting 8.14 1.48 1.66 2.10 Al and powder imp. As-Built 8.08 +/ 1.46 +/− 1.65 +/− 2.09 +/− Al and Components** 0.13 0.02 0.02 0.03 imp. *The impurities were less than 0.03 wt. % each and less than 0.10 wt. % in total. **Average composition of 24 as-built components with standard deviation shown as +/−.

[0037] The density of the as-built components was determined using an Archimedes density analysis procedure in accordance with NIST standards. The Archimedes density analysis revealed that densities in excess of 99% of the theoretical density were obtained within the as-built components.

[0038] The microstructure of the as-built components was analyzed via optical metallography (OM), scanning electron microscopy (SEM), electron probe microanalysis (EPMA), and transmission electron microscopy (TEM). OM was performed on specimens prepared by mounting sections of the as-built specimens in Bakelite and then grinding and polishing using a combination of polishing media. The OM analysis revealed less than 1% porosity to be present within the specimens, thereby confirming the Archimedes density results.

[0039] SEM imaging was performed using the same specimens prepared for OM analysis and revealed the presence of both a globular dispersoid phase (i.e., fine particles, unable to be re-dissolved back into solid solution) and a fine cellular phase, representative images of which are shown in FIGS. 2(A) and 2(B). Image analysis of one of these specimens was performed to determine the size distribution and volume fraction of the dispersoid phase. A single image with an area of >100 μm.sup.2 was used for the image analysis. The resulting analysis revealed that the dispersoids ranged in diameter from about 30 to 400 nm, with an average of about 75 nm. It was also determined that the volume fraction of the dispersoids was about 6.7%. EPMA revealed that the fine dispersoids were enriched in iron (Fe) and vanadium (V), and are believed to be of the Al.sub.12(Fe,V).sub.3Si type.

[0040] Transmission electron microscopy (TEM) was employed to determine the composition of the cell walls. Electron transparent TEM foils were prepared from both as-built and thermally treated specimens (treated at about 375° F. for about 18 hours) by mechanically thinning the specimens prior to applying a final electrojet polishing step using a solution consisting of nitric acid (HNO.sub.3) and methanol with an applied voltage of 20-30 volts. The TEM analysis revealed the cell walls to be enriched in copper (Cu) and iron (Fe).

[0041] It is anticipated that adding TiB.sub.2 (or a similar ceramic material) to an Al—Fe—V—Si—Cu ingot, followed by inert gas atomization process will produce particles having a homogenous distribution of TiB.sub.2 phase within the aluminum alloy matrix. These particles could be used in a powder to make additively manufactured products, such as those illustrated in FIGS. 1-2.

[0042] While various embodiments of the present disclosure have been described in detail, it is apparent that modifications and adaptations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and adaptations are within the spirit and scope of the present disclosure.