Document Type : Research Article

Authors

• Narjes Saadatmandfard ¹
• Gholam Hussain Borhani ²
• Seyed Akbar Miresmaeili Hafdani ¹
• Seyed Masoud Barekat ³

¹ Department of Materials Engineering, Malek-Ashtar University of Technology, Isfahan, Iran

² Materials science engineering MUT Isfahani Iran

³ Department of Materials Engineering, Malek-Ashtar University of Technology, Tehran, Iran

Abstract

In this article an attempt is made to prepare W-4.9Ni-2.1Fe alloy and W-4.9Ni-2.1Fe/Y₂O₃ composite by powder metallurgy route. A detailed experimental study was performed to characterize the influence of ceramic particles Y₂O₃ and Ca impurities on microstructure and mechanical properties. The raw powder materials were mixed and then mechanically milled for 3h in Ar atmosphere. Y₂O₃ powder was added to milled powders in the last 30 min of milling. The milled powders were cold compacted at 300 MPa in cylindrical form and then subjected to liquid phase sintering at 1470 ˚C in dried Hydrogen atmosphere. The sintered samples were characterized for microstructure studies (SEM equipped with EDS), physical properties (Density and Young’s modulus) and mechanical properties (Rockwell hardness and Compressive strength). All sintered samples exhibited sintered density in the range of 15.4 to 16 g/cm³ (94 to 99 % relative density). Y₂O₃ and Ca impurities had a controlled role on W grain size growth. The compressive strength of composite samples increased up to 800MPa for W-4.9Ni-2.1Fe-1 Y₂O₃. Uniform distribution of W spheroids in Ni-Fe matrix was observed in sintered samples. The mean grain size of sintered samples varied in the range of 12 to 30 𝜇m.

Keywords

• : “W-4.9Ni-2.1Fe”
• “Y2O3”
• “Impurity”
• “Mechanical properties”

Main Subjects

• Powder metallurgy