scholarly journals Laser Surface Modification of Aluminium Alloy AlMg9 with B4C Powder

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 402 ◽  
Author(s):  
Marek Sroka ◽  
Ewa Jonda ◽  
Wojciech Pakieła
Keyword(s):  
Surface Layer ◽  
Cross Sections ◽  
Heat Affected Zone ◽  
Microstructural Analysis ◽  
Base Material ◽  
Substrate Material ◽  
Laser Surface Modification ◽  
Protective Gas ◽  
B4c Powder ◽  
Carbide Particles

This paper presents the effects of laser treatment (fiber laser YLS-4000) on the microstructure and selected mechanical properties of the surface layer of AlMg (AlMg9) foundry alloy obtained by alloying with boron carbide (B4C). The correlation between laser alloying process parameters and selected properties of the formed layer was discussed. The studies were supported by microstructural analysis of the remelted zone (RZ), heat affected zone (HAZ), undissolved carbide particles, substrate material, and precipitates formed during rapid solidification. Metallographic investigations of the laser-treated layer were performed using optical microscopy and scanning electron microscopy (SEM). The elemental composition and a detailed analysis of chemical composition in micro-areas were carried out using energy dispersive X-ray spectroscopy (EDS). The remelting thickness, heat-affected zone (HAZ), and amount of base material in surface layers were determined. Microhardness tests were performed on transverse cross-sections of the remelted zone to obtain the hardness profiles in the base material (BM), remelted zone (RZ), and heat affected zone (HAZ). The hardness, roughness, and wear resistance measurements showed that the highest tribological properties of the obtained surface layer were achieved using 0.5 Bar protective gas (Ar) during alloying with B4C powder.

Structure Analyses of Experimental Welds Designed for Repair Welding of VVER 1000 Presssure Vessel

2015 ◽  
Vol 647 ◽  
pp. 131-140 ◽  
Author(s):  
Miroslava Matějová ◽  
Dagmar Jandová ◽  
Josef Kasl
Keyword(s):  
Heat Affected Zone ◽  
Microstructural Analysis ◽  
Base Material ◽  
Fusion Line ◽  
Structure Transformation ◽  
Repair Welding ◽  
Weld Joints ◽  
The Third ◽  
Energy Inputs ◽  
Welding Metal

Microstructural analysis and microhardness measurement of experimental repair weld joints were carried out in heat affected zone (HAZ) of the base material (BM) – steel 15Ch2NMFA after weld deposition of several layers by welding metal of Inconel FM 52. A temper bead welding (TBW) technique was used. Required microhardness up to 350 HV0.1 in heat affected zone of base material in distance 0.5 mm from fusion line was exceeded in all three experimental blocks with various welding energy inputs during deposition of three or five weld layers. Metallography showed reaustenitization and structure transformation in HAZ after the deposit of first layer in all three blocks. After deposit of the last layer the structure of HAZ in two blocks was tempered only and one variant of them have been recommended for futher technological tests. Structure of HAZ of the third block was not full tempered even after the last layer deposit.

Laser treatment with 625 Inconel powder of hot work tool steel using fibre laser YLS-4000

2018 ◽  
Vol 2 (92) ◽  
pp. 60-67
Author(s):  
L.A. Dobrzański ◽  
E. Jonda ◽  
W. Pakieła ◽  
M. Dziekońska
Keyword(s):  
Chemical Composition ◽  
Laser Treatment ◽  
Laser Cladding ◽  
Tool Steel ◽  
Heat Affected Zone ◽  
Base Material ◽  
Substrate Material ◽  
Inconel 625 ◽  
Fibre Laser ◽  
Weld Overlay

Purpose: The purpose of this investigation was to determine the changes in the surface layer (Inconel 625), obtained during the laser treatment of tool-steel alloy for hot work by the use high-power fibre laser. Design/methodology/approach: Observations of the layer structure, HAZ, and substrate material were made using light and scanning microscopy. The composition of elements and a detailed analysis of the chemical composition in micro-areas was made using the EDS X-ray detector. The thickness of the resulting welds, heat affected zone (HAZ) and the contribution of the base material in the layers was determined. Findings: As a result of laser cladding, using Inconel 625 powder, in the weld overlay microstructure characteristic zones are formed: at the penetration boundary, in the middle of weld overlay and in its top layer. It was found that the height of weld overlay, depth of penetration, width of weld overlay and depth of the heat affected zone grows together with the increasing laser power. Practical implications: Laser cladding is one of the most modern repair processes for eliminating losses, voids, porosity, and cracks on the surface of various metals, including tool alloys for hot work. Laser techniques allow to make layers of materials on the repaired surface, that can significantly differ in chemical composition from the based material (substrate material) or are the same. Originality/value: A significant, dynamic development in materials engineering as well as welding technologies provides the possibility to reduce the cost of production and operation of machinery and equipment, among others by designing parts from materials with special properties (both mechanical and tribological) and the possibility of regeneration of each consumed element with one of the selected welding technologies.

scholarly journals Analysis of Different Complex Multilayer PACVD Coatings on Nanostructured WC-Co Cemented Carbide

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 823
Author(s):  
Danko Ćorić ◽  
Mateja Šnajdar Musa ◽  
Matija Sakoman ◽  
Željko Alar
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Base Material ◽  
Single Layer ◽  
Production Costs ◽  
Structural Defects ◽  
Cemented Carbides ◽  
Material System ◽  
Tin Coating ◽  
Ticn Coating

The development of cemented carbides nowadays is aimed at the application and sintering of ultrafine and nano-sized powders for the production of a variety of components where excellent mechanical properties and high wear resistance are required for use in high temperature and corrosive environment conditions. The most efficient way of increasing the tribological properties along with achieving high corrosion resistance is coating. Using surface processes (modification and/or coating), it is possible to form a surface layer/base material system with properties that can meet modern expectations with acceptable production costs. Three coating systems were developed on WC cemented carbides substrate with the addition of 10 wt.% Co using the plasma-assisted chemical vapor deposition (PACVD) method: single-layer TiN coating, harder multilayer gradient TiCN coating composed of TiN and TiCN layers, and the hardest multilayer TiBN coating composed of TiN and TiB2. Physical and mechanical properties of coated and uncoated samples were investigated by means of quantitative depth profile (QDP) analysis, nanoindentation, surface layer characterization (XRD analysis), and coating adhesion evaluation using the scratch test. The results confirm the possibility of obtaining nanostructured cemented carbides of homogeneous structure without structural defects such as eta phase or unbound carbon providing increase in hardness and fracture toughness. The lowest adhesion was detected for the single-layer TiN coating, while coatings with a complex architecture (TiCN, TiBN) showed improved adhesion.

The Preparation of Submicron Precision Cross Sections by Dimpling With A ‘Flatting Tool’

1997 ◽  
Vol 480 ◽  
Author(s):  
Helen L. Humiston
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Microstructural Analysis ◽  
Complex Materials ◽  
Ion Milling ◽  
Step Procedure ◽  
Simple Step ◽  
Primary Advantage ◽  
Preparation Techniques ◽  
Support Grid

AbstractThe complex materials systems in VLSI devices require specialized preparation techniques for TEM microstructural analysis. For this purpose, it is desirable to obtain electron transparency in all material layers from the oxides used in dielectrics to refractory metals such as tungsten. The primary advantage of dimpling these materials is that ideal specimens are obtained for low angle ion milling. By dimpling both sides of the cross section with a padded flatting tool, a thicker specimen of 130μm at the outer rim of the 3mm disc is produced that narrows to the 125nm thickness fringes in the center. These samples do not require a copper support grid, thereby allowing for a lower milling angle of 2.5 degrees on both sides of the specimen. This technique provides a cross section that is electron transparent in all layers without the loss of oxides due to differential thinning rates of various materials at higher milling angles.It is generally thought that precision thinning through a submicron feature is not possible on the dimpler. However, a simple step-by-step procedure for this technique will be demonstrated and discussed.

Experimental Investigations on Aluminium Ultrasonic Welding Parameters

2014 ◽  
Vol 657 ◽  
pp. 306-310
Author(s):  
Lăcrămioara Apetrei ◽  
Vasile Rață ◽  
Ruxandra Rață ◽  
Elena Raluca Bulai
Keyword(s):  
Microstructural Analysis ◽  
Base Material ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Experimental Investigations ◽  
Welding Parameters ◽  
Material Structure ◽  
Welding Temperature ◽  
Wide Range ◽  
Made In

Research evolution timely tendencies, in the nonconventional technologies field, are: manufacture conditions optimization and complex equipments design. The increasing of ultrasonic machining use, in various technologies is due to the expanding need of a wide range materials and high quality manufacture standards in many activity fields. This paper present a experimental study made in order to analyze the welded zone material structure and welding quality. The effects of aluminium ultrasonic welding parameters such as relative energy, machining time, amplitude and working force were compared through traction tests values and microstructural analysis. Microhardness tests were, also, made in five different points, two in the base material and three in the welded zone, on each welded aluminium sample. The aluminum welding experiments were made at the National Research and Development Institute for Welding and Material Testing (ISIM) Timişoara. The ultrasonic welding temperature is lower than the aluminium melting temperature, that's so our experiments reveal that the aluminium ultrasonic welding process doesn't determine the appearance of moulding structure. In the joint we have only crystalline grains deformation, phase transformation and aluminium diffusion.

Yb:YAG Disc Laser Welding of Austenitic Stainless Steel Without Filler Material

2009 ◽  
Vol 410-411 ◽  
pp. 87-96 ◽  
Author(s):  
Markku Keskitalo ◽  
Kari Mäntyjärvi
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Cross Sections ◽  
Base Material ◽  
Tensile Tests ◽  
Solidification Cracking ◽  
Filler Material ◽  
Test Material ◽  
Butt Weld

The laser weldability of austenitic stainless steel (ASS) is good because of the material’s high absorptivity and favourable microstructure. There can be a slight possibility of solidification cracking at high welding speeds and low Crekv/Niekv ratios. Test welds were welded with a Yb:YAG disc laser. The test material was 3.2 mm EN 1.4404 2H C700 type stainless steel plate which was work hardened by cold rolling. The test materials were welded with different heat inputs ranging from 0.024 kJ/mm to 0.12 kJ/mm and with 300 mm and 200 mm focal lengths. The weld seams were square-groove welded as butt weld without filler material. The edges of the groove were made by mechanical or laser cutting. The hardness profiles from cross-sections of the welds were measured with a Vickers microhardness tester using 200 g weight. The mechanical properties were tested with tensile tests. The welds were classified with radiographic verification by an accredited laboratory. A number of the welds were fatigue tested with a bending fatigue tester. The mechanical properties (Rp 0.2%, Rm) of the laser welds were almost the same as in the base material except at the highest heat input. In the radiographic classification, the welds which were welded to the laser-cut edge were classified as class B (accepted). The other welds were classified as class D or C (rejected). The main reasons for the rejection of welds made on mechanically cut edges were lack of penetration or undercut of the weld. A problem with mechanically cut edges, and hence the welds, is that they can be non-square and bent edge. Fatigue tests and tensile tests gave no evidence of solidification cracking in the microstructure of the solidified parts of the welds.

Microstructural Characterization and Tensile Behavior of TA1 Titanium Alloy Sheet Welded by Electron Beam Welding

2021 ◽  
Vol 1027 ◽  
pp. 149-154
Author(s):  
Sen Dong Gu ◽  
Ji Peng Zhao ◽  
Rui Jie Ouyang ◽  
Yong Hong Zhang
Keyword(s):  
Titanium Alloy ◽  
Electron Beam ◽  
Fusion Zone ◽  
Heat Affected Zone ◽  
Electron Beam Welding ◽  
Base Material ◽  
Optical Microscope ◽  
Alloy Sheet ◽  
Tensile Behavior ◽  
Electron Backscattered Diffraction

In the present study, TA1 titanium alloy sheets with a thickness of 0.8mm were welded by electron beam welding. Microstructure of the welded region was investigated using optical microscope and electron backscattered diffraction. Then, the tensile test was conducted to analyse the tensile behavior of the welded sheets as well as the fractography of the fracture surfaces. It is shown that the mean grain size in the heat-affected zone is smaller than that in the fusion zone and base material. The strength of the base metal is lower than that of the fusion zone and heat-affected zone. The average values of the yield strength, tensile strength and elongation of the tensile specimens are 224MPa, 335MPa and 35%, respectively. In addition, the tensile specimens of the welded sheets suffer both ductile and brittle deformation during the tensile tests.

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