Please use this identifier to cite or link to this item: http://hdl.handle.net/10397/28237
Title: Improvement in cavitation erosion resistance of a copper-based propeller alloy by laser surface melting
Authors: Tang, CH
Cheng, FT
Man, HC 
Keywords: Cavitation erosion
Cu-Mn-Al-Ni-Fe
Laser surface melting
Manganese-nickel-aluminium bronze
Microstructure
Issue Date: 2004
Publisher: Elsevier
Source: Surface and coatings technology, 2004, v. 182, no. 2-3, p. 300-307 How to cite?
Journal: Surface and coatings technology 
Abstract: Laser surface melting (LSM) of manganese-nickel-aluminium bronze (MAB), a common marine propeller alloy, was performed with the aim of improving the cavitation erosion resistance. Melting was achieved using a 2-kW continuous wave Nd:YAG laser with different scanning speeds and beam diameters, yielding different values of laser fluence. LSM resulted in a melt layer with a thickness of a few hundred micrometer thick, with the microhardness value at the surface increased to more than twice that of as-received MAB. The microstructure of the melt layer is highly refined and homogenized and has a single-phase b.c.c. structure (β phase), in contrast to the complex and heterogeneous microstructure of as-received MAB. With optimum laser parameters (power=1 kW; scanning velocity=35 mm/s; spot diameter=2 mm), the cavitation erosion resistance in 3.5 wt.% NaCl solution was improved by 5.8 and 2.2 times compared with that of as-received MAB and nickel-aluminium bronze (NAB), respectively. The improvement in cavitation erosion resistance is attributable to increased hardness and also to a much more homogeneous microstructure. Detailed analysis of the evolution of the morphology of the cavitated surface by SEM revealed totally different damage mechanisms for untreated and laser surface-melted MAB. For untreated MAB, the cavitation attack started at the κI phase, followed by an attack at the α/β phase boundary during the initial stage and eventually developed into ductile tearing of the matrix. However, the laser surface-melted samples only exhibited slight grain boundary attack at the initial stage, being initiating from triple junctions. In addition, the damaged surface of the laser-treated samples showed fracture of a more brittle nature.
URI: http://hdl.handle.net/10397/28237
ISSN: 0257-8972
EISSN: 1879-3347
DOI: 10.1016/j.surfcoat.2003.08.048
Appears in Collections:Journal/Magazine Article

Access
View full-text via PolyU eLinks SFX Query
Show full item record

SCOPUSTM   
Citations

43
Last Week
0
Last month
0
Citations as of Sep 11, 2017

WEB OF SCIENCETM
Citations

38
Last Week
0
Last month
0
Citations as of Sep 22, 2017

Page view(s)

29
Last Week
1
Last month
Checked on Sep 18, 2017

Google ScholarTM

Check

Altmetric



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.