Laser welding of nickel-chromium-molybdenum-containing steels

Hastelloy X is a commercially available nickel-chromium-molybdenum superalloy with a good oxidation resistance, a good mechanical properties at high temperature and a significant formability; sine qua criteria for the choice of materials for the production of chambers turbojet combustion which is part of this study [1]. Arc welding technique is commonly used for the manufacturing of parts but the aeronautical requirements becoming increasingly severe especially in terms of reproducibility of geometry and metallurgical grade fillet weld. Laser welding is a viable method of assembly to meet these new demands by its automation to replace longer term the manual TIG welding. The high power CO2laser is extensively used for practical applications such as cutting and welding laser welding. The CO2laser is very used in the industry with regard to Yb:YAG laser which until now was not rather powerful but this changes. The aim of this study was to evaluate the effect of Yb:YAG laser beam parameters on the microstructure and mechanical properties of the laser beam welded superalloys Hastelloy X to define a field of weldability. The implementation of an experimental design approach is required due to the multitude of input parameters and the complexity of the phenomena involved [2-3].

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Assessing different patterns of laser welding with Nickel-Chromium (Ni-Cr) alloy for structures applicable to fixed prosthesis

Brazilian Dental Science ◽

10.14295/bds.2017.v20i2.1363 ◽

2017 ◽

Vol 20 (2) ◽

pp. 62

Author(s):

Jarbas Eduardo Martins ◽

Fábio V.R. Bastos Neto ◽

Danilo Antônio Duarte ◽

Ângela Toshie Araki

Keyword(s):

Laser Welding ◽

Statistical Significance ◽

Welding Process ◽

Laser Pulses ◽

Bending Test ◽

Control Group ◽

Nickel Chromium ◽

Significant Difference ◽

Group A ◽

Passive Fit

<p><span lang="EN-US">Among all desired requirements to dental prosthesis, marginal adaptation and passive fit are the most important. In some cases, in order to achieve these goals, it is necessary to cut and weld the teeth / implant-supported framework. Nowadays, the laser welding process shows a great advantage in comparison to other methods. The aim of this study was to evaluate the optimal laser welds point that is more appropriate to Ni-Cr prosthetic framework. A total of 60 specimens of Ni-Cr (35 mm x 4 mm) were designed and welded using a Nd:YAG laser device model EV 900. They were fixed in a metal piece 0.27 mm between the ends to be welded. All specimens were welded with 21 laser pulses diametrically opposed (frequency of 1.0Hz, load time 3.0 ms and 0.5 mm of diameter pulse). They were divided into three groups according to the electric current of the laser weld: A – 180A; B – 200A and C – 220A. To determinate the flexural mechanic strength, all specimens were submitted to a three-point bending test. The results obtained were: Group A = 553 Mpa; B = 751 Mpa and C = 802.1 Mpa. The control group was 1040.9 Mpa. ANOVA and Tukey’s test were performed and statistical significance differences were observed between group A and B as well as between group A and C. However, no significant difference was observed between B and C.</span></p>

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Laser Welding of a Nickel-Chromium Dental Alloy

Military Medicine ◽

10.1093/milmed/142.4.299 ◽

1977 ◽

Vol 142 (4) ◽

pp. 299-301 ◽

Cited By ~ 4

Author(s):

James C. Adrian ◽

Eugene F. Huget

Keyword(s):

Laser Welding ◽

Dental Alloy ◽

Nickel Chromium

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HREM observation of NiO growth on submicron spheres of pure nickel

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100154718 ◽

1989 ◽

Vol 47 ◽

pp. 548-549

Author(s):

C.M. Teng ◽

T.F. Kelly ◽

J.P. Zhang ◽

H.M. Lin ◽

Y.W. Kim

Keyword(s):

Nickel Oxide ◽

Grain Boundaries ◽

Pure Nickel ◽

Submicron Particles ◽

Crystal Formation ◽

Nickel Wire ◽

Liquid Droplets ◽

Oxide Interface ◽

Nickel Chromium ◽

Chromium Alloys

Spherical submicron particles of materials produced by electrohydrodynamic (EHD) atomization have been used to study a variety of materials processes including nucleation of alternative crystallization phases in iron-nickel and nickel-chromium alloys, amorphous solidification in submicron droplets of pure metals, and quasi-crystal formation in nickel-chromium alloys. Some experiments on pure nickel, nickel oxide single crystals, the nickel/nickel(II) oxide interface, and grain boundaries in nickel monoxide have been performed by STEM. For these latter studies, HREM is the most direct approach to obtain particle crystal structures at the atomic level. Grain boundaries in nickel oxide have also been investigated by HREM. In this paper, we present preliminary results of HREM observations of NiO growth on submicron spheres of pure nickel.Small particles of pure nickel were prepared by EHD atomization. For the study of pure nickel, 0.5 mm diameter pure nickel wire (99.9975%) is sprayed directly in the EHD process. The liquid droplets solidify in free-flight through a vacuum chamber operated at about 10-7 torr.

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