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., MARAŞLI N.

Metals and Materials International, vol.19, no.1, pp.39-44, 2013 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 19 Issue: 1
  • Publication Date: 2013
  • Doi Number: 10.1007/s12540-013-1007-4
  • Journal Name: Metals and Materials International
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.39-44
  • Keywords: Al-Ni alloy, dendritic microstructures, microhardness, electrical resistivity
  • Istanbul Gelisim University Affiliated: No

Abstract

Al-7 wt% Ni alloy was directionally solidified upwards with different growth rates, V (8.3-489.5 μm/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 (λ 1) and secondary dendrite arm spacing (λ 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 (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 λ 1 and λ 2. © 2013 The Korean Institute of Metals and Materials and Springer Science+Business Media Dordrecht.