Improving the Surface Properties of Cp-Ti by Pulsed Electro-Spark Deposition


Yilmaz M. S. , Atar E., Sahin O., Kayali E. S.

ACTA PHYSICA POLONICA A, cilt.125, ss.593-596, 2014 (SCI İndekslerine Giren Dergi) identifier

  • Cilt numarası: 125 Konu: 2
  • Basım Tarihi: 2014
  • Dergi Adı: ACTA PHYSICA POLONICA A
  • Sayfa Sayıları: ss.593-596

Özet

Al-Ti intermetallic compounds were coated by electro-spark deposition. Commercially pure titanium (Cp-Ti) (grade 2) and aluminum rods were used as substrate and electrode materials, respectively. During the electro-spark deposition experiments the following pulse parameters in a group were used: pulse current amplitude, pulse duration and pause between the pulses of a pulse group with 100-300-500 A, 50400 mu s, and 100 mu s, respectively. Al-Ti coatings haying a thickness range of 15-30 mu m were formed on the surface of titanium substrate using electro-spark deposition process. The coating properties such as the roughness and the thickness increased with increasing pulse duration and pulse current amplitude. The mass transfer coefficient decreased with increasing pulse current amplitude and pulse duration. The quality of the adhesion characters of the coatings, determined by Rockwell-C adhesion test, becomes worse from HF-2 to HF-4, due to increase of pulse current amplitude. Depending on the electro-spark deposition process parameters, the coating formed as AlTi or as layered structure consisting of AlTi+AlTi3 when pulse current amplitude increases. The Al-Ti coatings include some micro cracks lying throughout the coating from surface to interface which is nature of this process. The maximum cross-sectional hardness of the coatings were in the range of 800-150 HV.