Volume 29, Issue 1 (Jun 2010)
2010, 29(1): 21-30 |
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Department of Materials Engineering, Malek-Ashtar University of Technology , bakhshisr@ma.iut.ac.ir
Abstract: (8045 Views)
In this study, Mo-14Si-10B and Mo-57Si-10B (at%) elemental powders were separately milled using an attritor mill. Mechanically alloyed powders were agglomerated and annealed. Then, powders of Mo-Si-B as alloyed (with composites) and agglomerated (without composites) were plasma sprayed onto plain carbon steels. The samples, both coated and non-coated, were subjected to isothermal oxidation tests. Metallurgical characteristics of powders and coatings were evaluated by SEM and XRD. Plasma-sprayed Mo-Si-B coatings (with phases of MoSi2, Mo5Si3, MoB and Mo5SiB2) greatly improved the oxidation resistance of the plain steel substrates, but plasma-sprayed Mo-Si-B coatings (without any phases) did not significantly improve the oxidation rate of substrates. Also, the kinetics and composition of the oxide-scale have been found to depend on the alloy composition.
Keywords: Mechanical alloying, Thermal spraying, High temperature oxidation, Molybdenum silicides, Mo-Si-B.
Type of Study: Research |
Subject:
General
Received: 2015/02/9 | Accepted: 2015/05/5 | Published: 2015/05/5
Received: 2015/02/9 | Accepted: 2015/05/5 | Published: 2015/05/5