Steel surface hardening using cw CO2 laser: laser alloying and cladding, wear resistance mehanical assay of laser-treated surfaces

1996 ◽  
Author(s):  
German Muniz ◽  
Jorge Alum
Keyword(s):  
Wear Resistance ◽  
Co2 Laser ◽  
Surface Hardening ◽  
Steel Surface ◽  
Laser Alloying ◽  
Cw Co2 Laser

Effects of CO2 Laser Surface Hardening in the Unlubricated Wear of Ductile Cast Iron Against Alumina

1996 ◽  
Vol 118 (4) ◽  
pp. 748-752 ◽  
Author(s):  
C. Papaphilippou ◽  
M. Vardavoulias ◽  
M. Jeandin
Keyword(s):  
Wear Resistance ◽  
Cast Iron ◽  
Co2 Laser ◽  
Surface Hardening ◽  
Normal Load ◽  
Ductile Cast Iron ◽  
Laser Surface ◽  
Sliding Velocity ◽  
Wear Coefficient ◽  
Laser Surface Hardening

The microstructure of a ferrito-pearlitic ductile cast iron has been modified by CO2 laser surface hardening. Analysis of the laser-processed surfaces showed a dramatic increase in microhardness. Dry sliding wear of laser-treated specimens against an alumina counterbody has been investigated by “ball-on-disk” testing. The evolution of the wear coefficient, as well as metallographic observations, revealed an oxidational wear mechanism. The wear resistance of the laser-treated samples was significantly enhanced. The laser-treated cast iron has a better resistance to abrasion and plastic deformation. The improvement of the wear resistance was due to the fine and homogeneous microstructure produced after laser-treatment. Wear plots showing the evolution of wear coefficient with normal load, sliding velocity, and humidity have been established. The wear of the laser-treated cast iron is not influenced by the variation of operating conditions (normal load, sliding velocity, and relative humidity).

Investigations on cw CO2-laser induced welding plasmas using differential interferometry

1999 ◽  
Author(s):  
Henrik Schittenhelm ◽  
Jürgen Müller ◽  
Peter Berger ◽  
Helmut Hügel
Keyword(s):  
Co2 Laser ◽  
Differential Interferometry ◽  
Cw Co2 Laser

On effect of surface hardening on impact and abrasive wear resistance of Hadfi eld steel

2020 ◽  
pp. 252-255
Author(s):  
V.I. Bolobov ◽  
V.S. Bochkov ◽  
E.V. Akhmerov ◽  
V.A. Plashchinsky ◽  
E.A. Krivokrisenko E.A.
Keyword(s):  
Plastic Deformation ◽  
Wear Resistance ◽  
Abrasive Wear ◽  
Work Hardening ◽  
Surface Hardening ◽  
Cold Work ◽  
Abrasive Wear Resistance ◽  
Hadfield Steel ◽  
Mining Equipment ◽  
Effect Of Surface

On the example of Hadfield steel, as the most common material of fast-wearing parts of mining equipment, the effect of surface hardening by plastic deformation on their impact and abrasive wear resistance is considered. Wear test is conducted on magnetic ironstone as typical representative of abrasive and hard rock. As result of wear of initial samples with hardness of ∼200 HB and samples pre-hardened with different intensities to the hardness of 300, 337 and 368 HB, it is found that during the initial testing period, the initial samples pass the “self-cold-work hardening” stage with increase in hardness to ∼250 HB, which remains virtually unchanged during further tests; the hardness of the pre-hardened samples does not change significantly throughout the tests. It is established that the rate of impact-abrasive wear of pre-hardened samples is significantly (up to 1.4 times) lower than the original ones that are not subjected to plastic deformation, and decreases with increasing degree of cold-work hardening. Preliminary surface hardening by plastic deformation can serve as effective way to increase the service life of fast-wearing working parts of mining equipment.

Spatial temperature distribution in CW CO2 laser photosensitized reactions

1984 ◽  
Vol 49 (6) ◽  
pp. 1354-1359 ◽  
Author(s):  
Pavel Kubát ◽  
Josef Pola
Keyword(s):  
Temperature Distribution ◽  
Chemical Reactions ◽  
Co2 Laser ◽  
Computational Procedure ◽  
Heat Convection ◽  
Inert Gas ◽  
Spatial Temperature Distribution ◽  
Cw Co2 Laser ◽  
Spatial Temperature

The temperature distribution in gaseous SF6 and SF6-inert gas samples under irradiation with cw CO2 laser measured by a thermocouple technique is confronted with the results of a computational procedure neglecting heat convection. The results are helpful in understanding the effect of the inert gas on the distribution of temperature and the size of the reacting hot volume in the cw laser-photosensitized chemical reactions.

Cw CO2 laser driven oxidation of some perhalogenocycloalkenes

1991 ◽  
Vol 56 (2) ◽  
pp. 398-405 ◽  
Author(s):  
Josef Pola ◽  
Jaroslav Včelák ◽  
Zdeněk Chvátal
Keyword(s):  
Co2 Laser ◽  
Total Pressure ◽  
Diels Alder ◽  
Title Reaction ◽  
Consecutive Reactions ◽  
Cw Co2 Laser

The title reaction of hexafluorocyclobutene, 1,2-dichloro-3,3,4,4-tetrafluorocyclobutene and decafluorocyclohexene studied at total pressure 13.3 and 16 kPa yield oxalyl halides COX.COX (X = F, Cl) and C2F4 that undergo consecutive reactions to COF2, CO and X2. The oxidation of decafluorocyclohexene is preceded by retro-Diels-Alder decomposition affording hexafluorocyclobutene and C2F4. Two alternative mechanisms for the oxidation of the cyclobutenes are presented, one involving a novel cleavage of intermediary bicyclic dioxetanes. The decomposition of oxalyl fluoride into COF2 and CO is favored over its oxidation.

Influence of a radial inhomogeneity of the active medium on the output radiation power from a cw CO2 laser with fast axial flow

1996 ◽  
Author(s):  
Michail G. Galushkin ◽  
Vladimir S. Golubev ◽  
V. V. Dembovetsky ◽  
Yuri N. Zavalov ◽  
Valentina Y. Zavalova
Keyword(s):  
Active Medium ◽  
Co2 Laser ◽  
Radiation Power ◽  
Axial Flow ◽  
Output Radiation ◽  
Radial Inhomogeneity ◽  
Cw Co2 Laser ◽  
Output Radiation Power
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