Effects of La Microalloying on Microstructure Evolution of Pure Copper

Abstract:

The absorptivity of La in pure copper and the effects of La microalloying on microstructure evolution of pure copper were studied by adding different La contents to pure copper under vacuum condition. The microstructure of copper ingots with different La contents were synthetically analyzed by means of optical microscope (OM) and scanning electron microscope (SEM), and the content of La in ingots was tested using inductively coupled plasma-atomic emission spectrometry (ICP-AES). The results showws that the absorptivity of La in pure copper was more than 90% under vacuum condition and the burning rate was mainly determinated by autoxidation of La and the reaction with impurity elements in copper. The microstructure of copper ingot was refined with La addition. The columnar to equiaxed transition (CET) occured with 0.14% La addition and the microstructure of copper ingot was full equiaxed grains when La content was 0.16%. The CET mechanism was that the constitutional supercooling in copper melt was increased with La addition. The tensile strength of copper alloys could be improved slightly, while the elongation was decreased a little after La alloying.

• Periodical: Materials Science Forum (Volume 898)
• Pages: 361-366
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.898.361
• Online since: June 2017
• Authors: Jin Hu Wu*, Shi Hong Zhang, Yan Chen, Hai Hong Li, Jin Song Liu
• Keywords: Absorptivity, Microalloying, Microstructure Evolution, Pure Copper, Rare Earth

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