Effect of microstructural evolution and elevated temperature on the mechanical properties of Ni-Cr-Mo alloys

Karakose E., KESKİN M.

JOURNAL OF ALLOYS AND COMPOUNDS, vol.619, pp.82-90, 2015 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 619
  • Publication Date: 2015
  • Doi Number: 10.1016/j.jallcom.2014.09.036
  • Journal Name: JOURNAL OF ALLOYS AND COMPOUNDS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.82-90
  • Keywords: Metals and alloys, Solidification behavior, Hardness, Microstructure, SN-PB, SOLIDIFICATION, PRECIPITATION, REFINEMENT, PREDICTION, SPACINGS, HARDNESS, MODEL
  • Kayseri University Affiliated: No

Abstract

This paper characterizes the impact of solidification rate on the morphology and type of microstructural and mechanical properties of a nickel-based superalloy with a nominal composition of Ni-25Cr-18Mo (at.%) in a wide cooling range (5-100 K/s). The microstructures of the alloys were identified by scanning electron microscopy (SEM) and the phase composition was examined by X-ray diffractometry (XRD). The phase transitions during the solidification process were investigated by differential thermal analysis (DTA) under an Ar atmosphere. It was found that the final microstructure of Ni-25Cr-18Mo alloy mostly depends upon the solidification rate; the microstructures evolve from a coarse dendritic structure to a refined dendritic structure. The mechanical properties of Ni-25Cr-18Mo alloys were examined by using Vickers and Rockwell hardness tests at room temperature and at elevated temperatures from 400 degrees C to 800 C. It was found that the hardness values of the samples were connected with the cooling rate and test temperatures. (C) 2014 Elsevier B.V. All rights reserved.