Laser Surface Modification of a Crystalline Al-Co-Ce Alloy for Enhanced Corrosion Resistance

2005 ◽  
Vol 7 (9) ◽  
pp. 805-809 ◽  
Author(s):  
J. G. Hoekstra ◽  
S. B. Qadri ◽  
J. R. Scully ◽  
J. M. Fitz-Gerald
Keyword(s):  
Corrosion Resistance ◽  
Surface Modification ◽  
Laser Surface ◽  
Laser Surface Modification

Improvement Of Cavitation Erosion Resistance and Corrosion Resistance Of Brass by Laser Surface Modification

2000 ◽  
Vol 617 ◽  
Author(s):  
K. F. Tam ◽  
F. T. Cheng ◽  
H. C. Man
Keyword(s):  
Corrosion Resistance ◽  
Surface Modification ◽  
Cavitation Erosion ◽  
Continuous Wave ◽  
Erosion Resistance ◽  
Laser Surface ◽  
Hardness Profile ◽  
Anodic Current Density ◽  
Laser Surface Modification ◽  
Cavitation Erosion Resistance

AbstractLaser surface modification of brass (Cu-38Zn-1.5Pb) using AISiFe and NiCrSiB alloy was achieved by using a 2kW continuous wave Nd-YAG laser with the aim of improving the cavitation erosion resistance and corrosion resistance. The alloying powder was preplaced on the brass substrate by thermal spraying to a thickness of 350µm, followed by laser beam scanning to effect melting, mixing and alloying. A modified surface was achieved by overlapping of adjacent tracks. The cavitation erosion resistance and the anodic polarization characteristics of the laser surface modified specimens in 3.5% NaCI solution at 23°C were studied by means of a 20kHz ultrasonic vibrator at a peak to peak amplitude of 60µm and a potentiostat respectively. The cavitation erosion resistance of the specimens modified with AlSiFe and NiCrSiB was improved by a factor of 3 and 7 respectively, compared with that of the brass substrate. Potentiodynamic test, however, indicated that the corrosion resistance of specimens modified with AlSiFe deteriorated, as reflected by a shift of the polarization curve towards higher current densities. On the other hand, the corrosion resistance of specimens modified with NiCrSiB was significantly improved, as evidenced by the presence of a passive region (from −175 mV to −112 mV) and a reduction in the anodic current density by at least an order of magnitude compared with the substrate at the same anodic potential. The hardness profile and the compositional profile were measured using a Vickers hardness tester and EDX respectively. The microstructure and the surface morphology of the specimens were investigated with the aid of SEM and optical microscopy.

Effect of laser surface modification on the corrosion resistance of Alloy 600

1998 ◽  
Vol 107 (2-3) ◽  
pp. 94-100 ◽  
Author(s):  
Jin Koog Shin ◽  
Jeong Hun Suh ◽  
Joung Soo Kim ◽  
Suk-Joong L Kang
Keyword(s):  
Corrosion Resistance ◽  
Surface Modification ◽  
Laser Surface ◽  
Alloy 600 ◽  
Laser Surface Modification

Laser Surface Modification of Various Tool Steels for Improving Hardness and Corrosion Resistance

2008 ◽  
Vol 384 ◽  
pp. 125-155 ◽  
Author(s):  
C.T. Kwok ◽  
F.T. Cheng ◽  
Hau Chung Man ◽  
K.I. Leong
Keyword(s):  
Solid Solution ◽  
Corrosion Resistance ◽  
Surface Modification ◽  
High Speed ◽  
Surface Hardness ◽  
Processing Parameters ◽  
Laser Surface ◽  
Tool Steels ◽  
Laser Surface Modification ◽  
Polarization Technique

Laser surface modification of nine tool steels, namely, plastics mold steels (PMSs), high-speed steels (HSSs) and cold/hot-work steels (CHWSs), was achieved by means of a CW Nd:YAG laser. The microstructure and the phases present in the surface of the specimens were analyzed by optical microscopy, scanning-electron microscopy and X-ray diffractometry. The surface hardness of the specimens was measured using a Vickers microhardness tester. The corrosion characteristics of the laser surface-melted steels in 3.5 wt% NaCl solution at 25 oC were studied by potentiodynamic polarization technique. The microstructures of the surface of the steels were changed completely after laser surface melting. Some steels showed improved corrosion resistance compared with the conventionally hardened specimens due to dissolution of the alloying elements in solid solution. The hardness and corrosion characteristics of all the laser surface-melted specimens are strongly dependent on the amount of passivating elements in solid solution and also on the morphology of the re-precipitated carbides. Both these factors depend on the laser processing parameters and the substrate compositions.

Improved pitting corrosion resistance of cold worked and thermally aged AISI type 316 L(N) SS by laser surface modification

2007 ◽  
Vol 23 (2) ◽  
pp. 83-92 ◽  
Author(s):  
R.V. Subba Rao ◽  
N. Parvathavarthini ◽  
M. G. Pujar ◽  
R. K. Dayal ◽  
H. S. Khatak ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Surface Modification ◽  
Pitting Corrosion ◽  
Laser Surface ◽  
Laser Surface Modification ◽  
Aisi Type ◽  
Pitting Corrosion Resistance ◽  
Cold Worked
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