Investigation of laser surface alloying of copper on high nickel austenitic ductile iron

D. W. Zeng, C. S. Xie, Kam Chuen Yung

Research output: Journal article publicationJournal articleAcademic researchpeer-review

27 Citations (Scopus)

Abstract

Laser surface alloying (LSA) of pure copper on high nickel austenitic ductile iron was carried out using a 2 kW continuous wave (CW) CO2laser with two processing conditions: laser beam spot size D = 5 mm, scanning speed V = 2 mm s-1, power density E = 1.02 × 104W cm-2(condition 1) and D = 2 mm, V = 9 mm s-1, 6.37 × 104W cm-2(condition 2). Microstructure in the alloyed zone was found to consist mainly of primary γ-austenite dendrites and an interdendritic eutectic of γ-austenite and M7C3carbides with copper wetting the dendritic boundaries. Distribution of the copper in the alloyed zone is fairly uniform across the depth of the pool and the concentration of copper in the alloyed zone highly depends on the power density. Copper spheroidal particles can be observed at the interdendritic boundaries under condition 1, indicating that the melt could be near the metastable miscibility gap and liquid phase separation (LPS) takes place due to rapid solidification. After LSA, hardness of the alloyed zone is considerably higher than before, which is attributed to both precipitation hardening and work hardening caused by the thermal stress.
Original languageEnglish
Pages (from-to)223-231
Number of pages9
JournalMaterials Science and Engineering A
Volume333
Issue number1-2
DOIs
Publication statusPublished - 1 Jan 2002

Keywords

  • High nickel austenitic ductile iron
  • Laser surface alloying (LSA)
  • Liquid phae separation (LPS)
  • Power density

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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