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Microalloy layer formation by ion implantation
Thin Solid Films, 63 (1979) 1-2 © Elsevier Sequoia S.A., L a u s a n n e - - P r i n t e d in the Netherlands
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MICROALLOY LAYER FORMATION BY ION IMPLANTATION* S. T. PICRAUX, S. M. MYERS AND D. M. FOLLSTAEDT
Sandia Laboratories, Albuquerque, N.M. 87185 (U.S.A.)
Ion implantation is being increasingly recognized as an important new method for forming alloyed layers on the surfaces of metals ~-3. This approach has led to substantial improvements in material properties such as hardness, wear, fatigue, corrosion and superconductivity 3. Furthermore, studies of the evolution of implanted layers during annealing have yielded important new information on alloying processes in technological materials l'z. Many studies exploiting the various surface properties of materials which can be obtained by ion implantation are being carried out, and they provide motivation for obtaining an improved microscopic understanding of implanted layers in metals. This paper will review current understanding of the microscopic nature of such microalloy layers and will survey the wide variety of equilibrium 4"5 and non-equilibrium 4'6-8 materials obtainable by this process. Distinction will be made between ion implantation and related processes for surface layer modification, e.g. ion plating and ion nitriding. The power and versatility of ion implantation derive from the unique control provided by this non-equilibrium process. For example, both amorphous layers and non-equilibrium substitutional and interstitial solutions can be formed in this way at low temperatures. Increased substrate temperatures during or subsequent to implantation can lead to the formation of precipitated microalloy layers, but with characteristics not usually found in bulk alloys. Implantation-formed precipitate distributions, for example, can be much finer and denser than the distributions obtainable by conventional alloying processes and the implantation parameters provide for direct control over these size distributions. An additional special aspect to implant-formed layers is given by the intense radiation damage deposited by the implanted ions, and the microstructural consequences of this will be discussed. A greater degree of control over the implantation disorder, as well as over the precipitate microstructure, may become available as recent pulsed electron beam and laser beam annealing techniques are applied to implanted metals. This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under contract AT(29-1)789.
*Abstract of a paper presented at the International Conference on Metallurgical Coatings, San Diego. California, U.S.A., April 23-27, 1979.
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AUTHORS' ABSTRACTS
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Proc. Int. ('ol~/i on Ion Beam Modification of Materials, Budapest, 197,~, Radiat. Eff~, to be published. F. Chernow, J. A. Borders and D. K. Brice (eds.), Ion Implantation in Semiconductors, Plenum, New York, 1977. Inst. Phys. Coq/i Ser., 28 (1976). S . T . Picraux, Proc. N A T O Advanced Study Institute on Site Characterization and Aggregation c~/ hnplanted A toms in Materials, Aleria, Corsica, September, 1978, Plenum, New York, to be published. S.M. Myers, J. Vac. Sci. Technol., 15 (1978) 1650. J . A . Borders, Atom. Rev. Mater. Sci., 9, in the press. J . M . Poate, J. Vae. Sei. Teehnol., 15 (1978) 1636. W . A . Grant, J. Vac. Sci. Teehnol., 15 (1978) 1644.
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MICROALLOY LAYER FORMATION BY ION IMPLANTATION* S. T. PICRAUX, S. M. MYERS AND D. M. FOLLSTAEDT
Sandia Laboratories, Albuquerque, N.M. 87185 (U.S.A.)
Ion implantation is being increasingly recognized as an important new method for forming alloyed layers on the surfaces of metals ~-3. This approach has led to substantial improvements in material properties such as hardness, wear, fatigue, corrosion and superconductivity 3. Furthermore, studies of the evolution of implanted layers during annealing have yielded important new information on alloying processes in technological materials l'z. Many studies exploiting the various surface properties of materials which can be obtained by ion implantation are being carried out, and they provide motivation for obtaining an improved microscopic understanding of implanted layers in metals. This paper will review current understanding of the microscopic nature of such microalloy layers and will survey the wide variety of equilibrium 4"5 and non-equilibrium 4'6-8 materials obtainable by this process. Distinction will be made between ion implantation and related processes for surface layer modification, e.g. ion plating and ion nitriding. The power and versatility of ion implantation derive from the unique control provided by this non-equilibrium process. For example, both amorphous layers and non-equilibrium substitutional and interstitial solutions can be formed in this way at low temperatures. Increased substrate temperatures during or subsequent to implantation can lead to the formation of precipitated microalloy layers, but with characteristics not usually found in bulk alloys. Implantation-formed precipitate distributions, for example, can be much finer and denser than the distributions obtainable by conventional alloying processes and the implantation parameters provide for direct control over these size distributions. An additional special aspect to implant-formed layers is given by the intense radiation damage deposited by the implanted ions, and the microstructural consequences of this will be discussed. A greater degree of control over the implantation disorder, as well as over the precipitate microstructure, may become available as recent pulsed electron beam and laser beam annealing techniques are applied to implanted metals. This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under contract AT(29-1)789.
*Abstract of a paper presented at the International Conference on Metallurgical Coatings, San Diego. California, U.S.A., April 23-27, 1979.
2
AUTHORS' ABSTRACTS
1 2
Proc. Int. ('ol~/i on Ion Beam Modification of Materials, Budapest, 197,~, Radiat. Eff~, to be published. F. Chernow, J. A. Borders and D. K. Brice (eds.), Ion Implantation in Semiconductors, Plenum, New York, 1977. Inst. Phys. Coq/i Ser., 28 (1976). S . T . Picraux, Proc. N A T O Advanced Study Institute on Site Characterization and Aggregation c~/ hnplanted A toms in Materials, Aleria, Corsica, September, 1978, Plenum, New York, to be published. S.M. Myers, J. Vac. Sci. Technol., 15 (1978) 1650. J . A . Borders, Atom. Rev. Mater. Sci., 9, in the press. J . M . Poate, J. Vae. Sei. Teehnol., 15 (1978) 1636. W . A . Grant, J. Vac. Sci. Teehnol., 15 (1978) 1644.
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