Improvement of surface properties of iron based powder metal compacts by electroless Ni-B coating


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MATİK U.

JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY, cilt.33, ss.1603-1610, 2018 (SCI İndekslerine Giren Dergi)

  • Cilt numarası: 33 Konu: 4
  • Basım Tarihi: 2018
  • Doi Numarası: 10.17341/gazimmfd.416455
  • Dergi Adı: JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY
  • Sayfa Sayısı: ss.1603-1610

Özet

The effect of electroless Ni-B alloy coating on the hardness, friction, wear and corrosion resistance of iron based powder metal (PM) compacts were investigated. For this purpose, iron based PM compacts produced by powder metallurgy method were coated with electroless Ni-B alloy coating after a thin layer electroless Ni-P coating. Electroless Ni-B coated and uncoated PM compacts were characterized with scanning electron microscope (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and microhardness measurements. Tribological properties were determined using pin-on-disc type tribometer under loads of 10, 20 and 40 N, sliding speed of 1 ms-1 and sliding distance of 1000 m. Corrosion resistance of samples were determined by polarization measurements. The results show that electroless Ni-B coating has an amorphous structure and columnar growth morphology. Microhardness and tribological tests have shown that Ni-B coating improves the wear and friction properties of PM compacts with its high hardness and morphological properties. The electroless Ni-B coating caused a significantly increase in the corrosion resistance of PM compacts.