DEVELOPMENT AND CHARACTERIZATION OF LAB6 REINFORCED AL-5 WT.% SI HYBRID POWDERS AND COMPOSITES PREPARED BY MECHANICAL ALLOYING AND PRESSURELESS SINTERING

1 ERDOĞAN Ezgi Burcu
Co-authors:
1 MERTDİNÇ Sıddıka 1 TEKOĞLU Emre 1 AĞAOĞULLARI Duygu 1 ÖVEÇOĞLU M. Lütfi
Institution:
1 Istanbul Technical University, Chemical and Metallurgical Engineering Faculty, Metallurgical and Materials Engineering Department, Particulate Materials Laboratories (PML), Maslak, Istanbul, Turkey
Conference:
25th Anniversary International Conference on Metallurgy and Materials, Hotel Voronez I, Brno, Czech Republic, EU, May 25th - 27th 2016
Proceedings:
Proceedings 25th Anniversary International Conference on Metallurgy and Materials
Pages:
1234-1240
ISBN:
978-80-87294-67-3
ISSN:
2694-9296
Published:
14th December 2016
Proceedings of the conference were published in Web of Science and Scopus.
Metrics:
100 views / 16 downloads
Abstract

This study reports the effect of LaB6 particles on the Al-5 wt.% Si matrix powders and composites in regard of physical, microstructural and mechanical properties. Two different types of LaB6 particles such as laboratory-synthesized (LaB6(S)) and commercial (LaB6(C)) were used as reinforcement materials. (LaB6(S)) were prepared by mechanochemical synthesis (for 5 h) and leaching (4 M HCl) of La2O3-B2O3-Mg powder blends. In order to obtain hybrid powders, Al-5 wt.% Si-2 wt.% LaB6(S) and Al-5 wt.% Si-2 wt.% LaB6(C) blends were mechanically alloyed (MA'd) for 1, 4 and 8 h in a high-energy ball mill. A hydraulic press with a uniaxial pressure of 450 MPa was used for the compaction of the as-blended/MA’d powders. Green compacts were sintered at 570 °C for 2 h under Ar gas. X-ray diffractometry (XRD) and scanning electron microscopy (SEM) techniques were utilized for the phase and microstructural characterization of the as-blended/MA'd powders and sintered composites. Particle size analysis (PSA) and differential scanning calorimetry (DSC) technique were also conducted on the powder products. Sintered samples were characterized by density and Vickers microhardness measurements and sliding wear tests. With applying MA, physical and mechanical improvements in composite properties were observed. Al-5 wt.% Si-2 wt.% LaB6(C) MA’d for 8 h had the highest density value of 98.11%. Al-5 wt.% Si-2 wt.% LaB6(S) MA’d for 4 h had the highest microhardness value of 115.25±10.12 MPa. Al-5 wt.% Si-2 wt.% LaB6(C) MA’d for 4 h has lower wear volume loss value (0.441) than that of Al-5 wt.% Si-2 wt.% LaB6(S).

Keywords: Aluminum composites, mechanochemical synthesis, mechanical alloying, pressureless sintering

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