Hyperbaric laser chemical vapor deposition of high-strength aluminum- silicon-carbide nanocomposite fibers for aerospace and transportation applications

Conference Dates

November 10-14, 2019


For over 25 years, hyperbaric pressure laser chemical vapor deposition (HP-LCVD) has been studied by various authors as a mean for growing three-dimensional structures and fibers [1-2]. Novel normally-immiscible materials (NIMs) [3], amorphous/glassy ceramics [4], and high-strength fibers have been grown [5]. However, the highest experimental pressures to date have only reached beyond the critical point of certain alkanes (<60 bar) [6]. Our group has found it useful to synthesize materials from high pressure fluids, where the ensuing cooling rates after deposition can exceed 106 K/s. This has enabled the growth of (metastable) amorphous and nanostructured materials, including diamond-like carbon and boron carbides [7-8]. For this work, freestanding nanocomposite fibers were grown from mixtures of Bis(trimethylsilyl)methane and various organometallic and halide aluminum precursors. A chopped, cw fiber laser at 1064nm and diode lasers at 808nm were used for this work. The 1/e2 laser beam waists were approximately 10-15 microns across. The resulting Al-Si-C fibers could be grown continuously—and were nanostructured due to the precursor pressures and laser powers employed. A variety of phases were found to be present, including aluminum carbide, silicon carbide, carbon, and silicon-rich phases. Scanning electron microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) were used to characterize the composition and structure of the resulting materials. A map of the ternary phase diagram under these non-equilibrium conditions will be provided and discussed in detail. These fibers will find utility in reinforcements for ceramic- and metal-matrix composites for aerospace and transportation applications.


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[2]J. L. Maxwell, US Patent #5,786,023, 1996.

[3]J. L. Maxwell, M. R. Black, C. A. Chavez, K. R. Maskaly, M. Espinoza, M. Boman, Applied Physics A-Materials Science and Engineering, 2008, 91, 507.

[4]F. T. Wallenberger, P. C. Nordine, Journal of Materials Research, 1994, 9, 527.

[5]M. Boman, D. Bauerle, Journal of the Chinese Chemical Society, 1995, 42, 405.

[6] J. Maxwell, Unpublished Results.

[7]J. Maxwell, M. Boman, W. Springer, J. Narayan, S. Gnanavelu, Journal of the American Chemical Society, 2006, 128, 4405.

[8]J. Maxwell, C. Chavez, W. Springer, K. Maskaly, D. Goodin, Diamond and Related Materials, 2007, 16, 1557.

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