Phase transitions in Nb rich coating produced by laser alloying: a synchrotron radiation diffraction study

Costa, Adilson Rodrigues da; Craievich, A. F.; Vilar, R.

doi:10.1016/s0921-5093(01)01958-x

Cited by 13 publications

(3 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There is a modification in the microstructure as revealed by the additional Bragg peak (due to Nb 2 C) appearing at high temperature. Once formed, this phase is stable and remains, unchanged during long isothermal treatments at the above mentioned temperatures 3 . For Nb coating the main phases present in the reference state (a laser alloyed coating sample at room temperature) were identified as being Nb and NbC.…”

Section: Resultsmentioning

confidence: 97%

Niobium and chromium rich coatings tailored by laser alloying: XRD analysis at high temperatures

Costa

Craievich

Vilar³

2004

Mat. Res.

View full text Add to dashboard Cite

Laser treatment technologies have been widely used to modify superficial layers of different materials. In this work we prepare Nb and Cr rich coatings according to laser alloying technique using cast iron as substrate material. Nb and Cr are intensive used in order to overcome challenges like good chemical and mechanical performance at high temperatures. Following laser alloying the surface-modified samples were submitted to an "in situ" XRD analysis under controlled high temperature and atmosphere. The phase transitions registered point to transformations that do not implies formation of fragile phases or cracks induced by high volumes modifications.

show abstract

Section: Resultsmentioning

confidence: 97%

Niobium and chromium rich coatings tailored by laser alloying: XRD analysis at high temperatures

Costa

Craievich

Vilar³

2004

Mat. Res.

View full text Add to dashboard Cite

show abstract

“…This process is a non-equilibrium method of surface modification reaching cooling rates around 103-108 K/s, which are considerably high. The resultant microstructures, some of them metastable phases, are mainly composed of unique properties that are only obtained with this process and not with conventional ones [22,23]. Laser hardening is usually constrained to low heat inputs in order to avoid surface microcracks in ductile irons, resulting in shallow hardened layers [24].…”

Section: Laser Surface Hardened Meltingmentioning

confidence: 99%

Microcracks Reduction in Laser Hardened Layers of Ductile Iron

Hurtado-Delgado¹,

Huerta-Larumbe²,

Pérez³

et al. 2021

Coatings

View full text Add to dashboard Cite

A study of surface hardening of Ductile Iron (DI) with and without austempering heat treatment was developed. The chemical composition of the material contains alloying elements such as Cu and Ni, that allow to obtain a Ductile Iron Grade 120-90-02, based on ASTM A536, which was heat treated to be transformed to Austempered Ductile Iron (ADI). Specimens of 10 × 10 × 5 mm3 were obtained for application of surface hardening by Nd:YAG UR laser of 150 W maximum power. The parameters used were advance speed of 0.2 and 0.3 mm/s and power at 105, 120, 135 and 144 W; the departure microstructures were fully pearlitic in the samples without heat treatment, and ausferrite for austempered samples. Microstructural characterization of hardened samples was performed were analyzed and martensite and undissolved carbides were identified in the pearlitic samples, while in ausferrite samples it was found finer martensite without carbides. The depth of hardened surface to different conditions and their respective microhardness were measured. The results indicate that the surface hardening via laser is a suitable method for improving wear resistance by means of hardness increment in critical areas without compromising the core ductility of DI components, but the surface ductility is enhanced when the DI is austempered before the laser hardening, by the reduction of surface microcracks.

show abstract

“…Laser surface engineering, which is based on the principle of laser material surface modification and/or manufacturing, has been recognized as a promising technology than rest of surface modification methods, due to its flexibility and a non-equilibrium method to produce higher cooling rates (10 3 -10 8 Ks −1 ) [3,4]. Several microstructural variations with unique properties that cannot be produced using conventional technique can be attained through laser processing [5]. Laser processing includes quenching [6], surface hardening [7], surface melting [8][9][10], laser surface alloying (LSA) [11,12] and cladding [13,14].…”

Section: Introductionmentioning

confidence: 99%

Archives of Metallurgy and Materials

Jeyaprakash¹,

Duraiselvam²,

Ramesh³

2018

View full text Add to dashboard Cite

The wear behaviour of Cr 3 C 2 -25% NiCr laser alloyed nodular cast iron sample were analyzed using a pin-on-disc tribometer. The influence of sliding velocity, temperature and load on laser alloyed sample was focused and the microscopic images were used for metallurgical examination of the worn-out sites. Box-Behnken method was utilised to generate the mathematical model for the condition parameters. The Response Surface Methodology (RSM) based models are varied to analyse the process parameters interaction effects. Analysis of variance was used to analyse the developed model and the results showed that the laser alloyed sample leads to a minimum wear rate (0.6079×10 -3 to 1.8570×10 -3 mm 3 /m) and coefficient of friction (CoF) (0.43 to 0.53). From the test results, it was observed that the experimental results correlated well with the predicted results of the developed mathematical model.

show abstract

Phase transitions in Nb rich coating produced by laser alloying: a synchrotron radiation diffraction study

Cited by 13 publications

References 4 publications

Niobium and chromium rich coatings tailored by laser alloying: XRD analysis at high temperatures

Niobium and chromium rich coatings tailored by laser alloying: XRD analysis at high temperatures

Microcracks Reduction in Laser Hardened Layers of Ductile Iron

Archives of Metallurgy and Materials

Contact Info

Product

Resources

About