Characteristics and high temperature wear behavior of chrome vanadium carbide composite coatings produced by thermo-reactive diffusion


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Günen A., Gök M. S. , Kanca E., Kurt B., Karakaş M. S. , Karahan İ. H. , ...Daha Fazla

Surface & Coatings Technology, cilt.402, no.126402, ss.1-14, 2020 (SCI İndekslerine Giren Dergi)

  • Cilt numarası: 402 Konu: 402
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1016/j.surfcoat.2020.126402
  • Dergi Adı: Surface & Coatings Technology
  • Sayfa Sayıları: ss.1-14

Özet

In this study, Cr–V–C composite carbide layers were grown on the surface of a GGG-80 ductile iron using thermoreactive diffusion (TRD). The TRD process was carried out at temperatures of 900, 1000, and 1100 °C for 1 h using nano-sized FeeV and FeeCr powders. The coatings were characterized by X-ray diffractometry (XRD), 2D profilometry, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), microhardness measurements, nanoindentation, and wear tests. The wear tests were performed on untreated and coated samples using a ball-on-disc type wear tester under 10 N load at four different temperatures (25 °C, 250 °C, 500 °C and 750 °C) against a 6-mm WC ball. Metallographic investigations revealed that the graphite nodules near the surface were dissolved as a result of the TRD process. Depending on the TRD process temperature, a coating with a thickness of 12–36 μm, hardness of 24.14–31.38 GPa, and elastic modulus of 198–233 GPa was obtained. An increase in process temperature increased the thickness, hardness, and elastic modulus of the obtained Cr–V–C layers, which resulted in low friction coefficient values and decreased wear rates. Although all coated samples showed improved wear resistance in all wear test conditions, the wear rates were significantly increased at 750 °C due to flaking.