Influence of growth rate on microstructure, microhardness, and electrical resistivity of directionally solidified Al-7 wt% Ni hypo-eutectic alloy


KAYA H. , Böyük U., Çadırlı E. , Maraşlı N.

METALS AND MATERIALS INTERNATIONAL, vol.19, no.1, pp.39-44, 2013 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 19 Issue: 1
  • Publication Date: 2013
  • Doi Number: 10.1007/s12540-013-1007-4
  • Title of Journal : METALS AND MATERIALS INTERNATIONAL
  • Page Numbers: pp.39-44

Abstract

Al-7 wt% Ni alloy was directionally solidified upwards with different growth rates, V (8.3-489.5 µm/s) at constanttemperature gradient, G (4.2 K/mm) using a Bridgman-type growth apparatus. The dependence of thedendritic microstructures such as primary dendrite arm spacing (λ1) and secondary dendrite arm spacing(λ2) on the growth rate were determined using a linear regression analysis. The present experimental resultswere also compared with similar previous experimental results. Measurements of microhardness (HV) and electrical resistivity (ρ) of the directionally solidified samples were carried out. The dependence of the microhardness and electrical resistivity on the growth rate (V) was also analyzed. According to these results, it has been found that, for increasing values of V, the values of HV and ρ increase. However, the values of HV and ρ decrease with increasing values of λ1 and λ2.

Al-7 wt% Ni alloy was directionally solidified upwards with different growth rates, V (8.3-489.5 mu m/s) at constant temperature gradient, G (4.2 K/mm) using a Bridgman-type growth apparatus. The dependence of the dendritic microstructures such as primary dendrite arm spacing (lambda (1)) and secondary dendrite arm spacing (lambda (2)) on the growth rate were determined using a linear regression analysis. The present experimental results were also compared with similar previous experimental results. Measurements of microhardness (HV) and electrical resistivity (rho) of the directionally solidified samples were carried out. The dependence of the microhardness and electrical resistivity on the growth rate (V) was also analyzed. According to these results, it has been found that, for increasing values of V, the values of HV and rho increase. However, the values of HV and rho decrease with increasing values of lambda (1) and lambda (2).