• Chinese Journal of Lasers
  • Vol. 32, Issue 7, 1011 (2005)
[in Chinese]1、2、* and [in Chinese]1
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  • 1[in Chinese]
  • 2[in Chinese]
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    [in Chinese], [in Chinese]. Effects of La2O3 on Microstructure and Properties of Laser Clad γ/Cr7C3/TiC Composite Coatings on TiAl Intermetallic Alloy[J]. Chinese Journal of Lasers, 2005, 32(7): 1011 Copy Citation Text show less

    Abstract

    The effects of La2O3 addition on microstructure, wear and oxidation properties of laser clad composite coatings on TiAl intermetallic alloy substrates with NiCr-Cr3C2 precursor mixed powders have been investigated. The corresponding wear and oxidation mechanisms are also discussed based on the experimental results. The results show that no evident new crystallographic phases are formed except a rapidly solidified microstructure consisting of the primary hard Cr7C3 and TiC carbides and the γ/Cr7C3 eutectics distributed in the tough γ nickel solid solution matrix. The additions of rare earth oxide La2O3 can refine and purify the microstructure of the coatings, relatively decrease the volume fraction of primary blocky Cr7C3 to Cr7C3/γ eutectics and increase the microhardness of the coatings. The refinement of the microstructure is beneficial to improving the microhardness, strength and toughness of the coatings, the purification and compactness of the coatings is in favor of the wear and oxidation resistance. The composite coating with 4 wt.-% La2O3 addition can result the best enhancement of wear and oxidation resistance. However, too less or excessive addition amount of La2O3 have no better influence on wear and oxidation properties of the composite coatings.
    [in Chinese], [in Chinese]. Effects of La2O3 on Microstructure and Properties of Laser Clad γ/Cr7C3/TiC Composite Coatings on TiAl Intermetallic Alloy[J]. Chinese Journal of Lasers, 2005, 32(7): 1011
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