The influence of various cooling rates during laser alloying on nodular iron surface layer

2018 ◽  
Vol 102 ◽  
pp. 60-67 ◽  
Author(s):  
Marta Paczkowska ◽  
Natalia Makuch ◽  
Michał Kulka
Keyword(s):  
Surface Layer ◽  
Iron Surface ◽  
Laser Alloying ◽  
Cooling Rates ◽  
Nodular Iron

THE POSSIBILITIES OF STRENGTHENING OF THE SURFACE LAYER OF NODULAR IRON BY LASER ALLOYING WITH SILICON NITRIDE ON THE EXAMPLE OF A ROCKER ARM

Tribologia ◽  
2017 ◽  
Vol 276 (6) ◽  
pp. 71-78
Author(s):  
Marta PACZKOWSKA
Keyword(s):  
Surface Layer ◽  
Silicon Nitride ◽  
Core Material ◽  
Beam Power ◽  
Laser Alloying ◽  
Dendritic Microstructure ◽  
Nodular Iron ◽  
Laser Beam Power ◽  
The One ◽  
Treatment Variant

In the order to increase the resistance to the friction wear of machine parts appropriate surface treatment application is needed. The aim of presented research was to evaluate the laser alloying with silicon nitride effects obtained in the surface layer of nodular iron and to select the laser treatment parameters that should be appropriate for the treatment of the one of the engine parts, which is a rocker arm. After implementation of silicon nitride into the nodular iron surface layer using laser heating, a uniform, fine, dendritic microstructure similar to the hardened white cast of the allayed zone was created in all performed variants. This microstructure resulted in at least 4-times higher hardness in comparison to the core material. The hardness and the alloyed zone dimensions were dependent on the laser heat treatment variant. The laser beam power density of 41 W/mm2 and its velocity of 2.8 mm/s were selected for the treatment of the rocker arm. It was caused by the effects obtained in the surface layer. With these parameters, it was possible to achieve the hardness of 1300 HV0.1 and the width of the alloying zone of over 4 mm, which is enough to strengthen the surface area of the rocker arm most exposed to the tribological wear.

scholarly journals Microstructure and tribological evolution during laser alloying WC-12%Co and Cr3C2−25%NiCr powders on nodular iron surface

2019 ◽  
Vol 12 ◽  
pp. 1610-1620 ◽  
Author(s):  
N. Jeyaprakash ◽  
Che-Hua Yang ◽  
Muthukannan Duraiselvam ◽  
G. Prabu
Keyword(s):  
Iron Surface ◽  
Laser Alloying ◽  
Nodular Iron

Ni Content Surface Layer Produced by Laser Surface Treatment on Amorphisable Cu Base Alloy

2010 ◽  
Vol 649 ◽  
pp. 101-106
Author(s):  
Mária Svéda ◽  
Dóra Janovszky ◽  
Kinga Tomolya ◽  
Jenő Sólyom ◽  
Zoltán Kálazi ◽  
...  
Keyword(s):  
Surface Layer ◽  
Surface Treatment ◽  
Laser Cladding ◽  
Base Alloy ◽  
Laser Surface ◽  
Laser Alloying ◽  
Laser Surface Treatment ◽  
Ni Content ◽  
Wide Range ◽  
The Matrix

The aim of our research was to comparatively examine Ni content surface layers on amorphisable Cu base alloy produced by different laser surface treatments. Laser surface treatment (LST) techniques, such as laser surface melting, laser alloying and laser cladding, provide a wide range of interesting solutions for the production of wear and corrosion resistant surfaces. [1,2] With LST techniques, the surface can be: i) coated with a layer of another material by laser cladding, ii) the composition of the matrix can be modified by laser alloying. [3] Two kinds of laser surface treatment technologies were used. In the case of coating-melting technology a Ni content surface layer was first developed by galvanization, and then the Ni content layer was melted together with the matrix. In the case of powder blowing technology Ni3Al powder was blown into the layer melted by laser beam and Argon gas. LST was performed using an impulse mode Nd:YAG laser. The laser power and the interaction time were 2 kW and 20÷60 ms. The characterization of the surface layer microstructure was performed by XRD, scanning electron microscopy and microhardness measurements.

THE INFLUENCE OF BORON IN THE SURFACE LAYER ON THE STRUCTURE AND THE TRIBOLOGICAL PROPERTIES OF IRON ALLOYS

Tribologia ◽  
2019 ◽  
Vol 288 (6) ◽  
pp. 73-80
Author(s):  
Aleksandra Pertek-Owsianna ◽  
Karolina Wiśniewska-Mleczko ◽  
Adam Piasecki
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Surface Layer ◽  
Steel Substrate ◽  
Eutectic Mixture ◽  
Iron Alloys ◽  
Boron Steel ◽  
Laser Alloying ◽  
Scanning Velocity ◽  
Steel Core

This paper presents two methods of introducing boron into the surface layer of iron alloys, namely diffusion boronizing by means of the powder method and laser alloying with a TRUMPF TLF 2600 Turbo CO2 gas laser. Amorphous boron was used as the chemical element source. As regards diffusion drilling, the influence of temperature and time on the properties of the layer was tested. During the laser alloying, the influence of the thickness of the boriding paste layer as well as the power and laser beam scanning velocity was determined. How the carbon content in steel and alloying elements in the form of chromium and boron influence the structure of the surface layer was tested. To achieve this object, the following grades of steel were used: C45, C90, 41Cr4, 102Cr6, and HARDOX boron steel. The microhardness and wear resistance of the obtained boron-containing surface layers were tested. A Metaval Carl Zeiss Jena light microscope and a Tescan VEGA 5135 scanning electron microscope, a Zwick 3212B microhardness tester, and an Amsler tribotester were used for the tests. The structure of the diffusion- borided layer consists of the needle-like zone of FeB + Fe2B iron borides about 0.15 mm thick, with a good adhesion to the substrate of the steel subjected to hardening and tempering after the boriding process. After the laser alloying, the structure shows paths with dimensions within: width up to 0.60 mm, depth up to 0.35 mm, containing a melted zone with a eutectic mixture of iron borides and martensite, a heat affected zone with a martensitic-bainitic structure and a steel core. The microhardness of both diffusionborided and laser-borided layers falls within the range of 1000 – 1900 HV0.1, depending on the parameters of the processes. It has been shown that, apart from the structure and thickness of the layer containing boron and microhardness, the frictional wear resistance depends on the state of the steel substrate, i.e. its chemical composition and heat treatment. The results of testing iron alloys in the borided state were compared with those obtained only after the heat treatment.

scholarly journals Microstructure of Fe–TiC Composite Surface Layer on Carbon Steel Formed by Laser Alloying Process

2013 ◽  
Vol 54 (9) ◽  
pp. 1755-1759 ◽  
Author(s):  
Takuto Yamaguchi ◽  
Hideki Hagino ◽  
Mamoru Takemura ◽  
Yasunori Hasegawa ◽  
Yasuhiro Michiyama ◽  
...  
Keyword(s):  
Surface Layer ◽  
Carbon Steel ◽  
Laser Alloying ◽  
Composite Surface

Glass-Ceramics of the Wollastonite - Tricalcium Phosphate-Silica System

2009 ◽  
Vol 1243 ◽  
Author(s):  
Jorge López-Cuevas ◽  
Martín I. Pech-Canul ◽  
Juan C. Rendón-Angeles ◽  
José L. Rodríguez-Galicia ◽  
Carlos A. Gutiérrez-Chavarría
Keyword(s):  
Surface Layer ◽  
Binary System ◽  
Tricalcium Phosphate ◽  
Body Fluid ◽  
Glass Melting ◽  
Glass Ceramics ◽  
Cooling Rates ◽  
Synthesized Materials

ABSTRACTGlass-ceramics based on hypo-eutectic (GC1) and hyper-eutectic (GC2) compositions of the Wollastonite (W, CaSiO3) - Tricalcium Phosphate [TCP, Ca3(PO4)2] binary system, which are saturated with SiO2 during the glass melting stage, are synthesized by the petrurgic method, using cooling rates of 0.5, 1 or 2°C/h. All synthesized materials are subjected to in vitro bioactivity tests using Kokubo's Simulated Body Fluid (SBF). Primary a-Cristobalite is formed in all cases. Metastable Apatite [Ap, Ca10(PO4)6O] and W phases are additionally formed, in general, in the GC1 glass-ceramics, as well as in the GC2 material obtained at a cooling rate of 0.5°C/h. However, at faster cooling rates, TCP is formed instead of Ap phase in the latter composition. During the bioactivity tests, a hydroxyapatite [HAp, Ca10(PO4)6(OH)2]-like surface layer is formed in all materials. It is proposed that GC2 glass-ceramics cooled at a rate of 1°C/h have the potential to show good in vivo osseointegration properties.

scholarly journals Microstructure, phase composition and corrosion resistance of Ni2O3 coatings produced using laser alloying method

2016 ◽  
Vol 36 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Aneta Bartkowska ◽  
Damian Przestacki ◽  
Tadeusz Chwalczuk
Keyword(s):  
Corrosion Resistance ◽  
Surface Layer ◽  
Phase Composition ◽  
Laser Beam ◽  
Nickel Oxide ◽  
Heat Affected Zone ◽  
Laser Alloying ◽  
Nickel Oxides ◽  
Thickness Increase ◽  
Good Corrosion Resistance

Abstract The paper presents the studies' results of microstructure, microhardness, cohesion, phase composition and the corrosion resistance analysis of C45 steel after laser alloying with nickel oxide (Ni2O3). The aim of the laser alloying was to obtain the surface layer with new properties through covering C45 steel by precoat containing modifying compound, and then remelting this precoat using laser beam. As a result of this process the surface layer consisting of remelted zone and heat affected zone was obtained. In the remelted zone an increased amount of modifying elements was observed. It was also found that the surface layer formed during the laser alloying with Ni2O3 was characterized by good corrosion resistance. This property has changed depending on the thickness of the applied precoat. It was observed that the thickness increase of nickel oxides precoat improves corrosion resistance of produced coatings.

The transformation of α-iron to γ-iron during abrasion

1954 ◽  
Vol 223 (1153) ◽  
pp. 167-174 ◽  
Keyword(s):  
Surface Layer ◽  
Electron Diffraction ◽  
Orientation Relationship ◽  
Iron Surface ◽  
Plane Parallel ◽  
Iron Crystal ◽  
Diffraction Patterns

Abrasion of the nearly (110) surface of an iron crystal, by a single 10 in. stroke on 0000 emery with light hand pressure, led to a disorientated α-iron surface layer containing some randomly disposed γ-iron. After etching away this and the neighbouring rotationally disorientated layer of α-iron, a strongly orientated layer of face-centred cubic γ-iron was exposed (with a = 3-60 A), the orientations being independent of the abrasion direction, with a {001} γ plane parallel to a {110} α plane of the α-iron crystal, and a<110> γ row of this face lying parallel to a<110> γ row of this {110} α plane. These γ-lattices were of lamellar form on {111} γ, with {111} twinning. The formation of this y-iron indicates that a rise in temperature of the order of 900° C had been caused at the surface by even this light abrasion. Other electron-diffraction patterns at this stage of etching showed that the α-iron main crystal was exposed in some regions and was bounded by {110} facets, which evidently correspond to the interfaces between the γ- and α-iron. This precisely determined orientation relationship differs from those found by Kurdjumow & Sachs, Nishiyama, and others, and indicates a mechanism of transformation simpler than those hitherto suggested, involving a shear on {211} α along <111> α as in normal {211} twinning.

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