Nanostructure Layer Formation on Cu-Zr-Al Alloy during Laser Remelting

2012 ◽  
Vol 729 ◽  
pp. 272-277
Author(s):  
Mária Svéda ◽  
Dóra Janovszky ◽  
K. Tomolya ◽  
J. Sólyom ◽  
G. Buza ◽  
...  
Keyword(s):  
Surface Layer ◽  
Laser Power ◽  
Amorphous Layer ◽  
Al Alloy ◽  
Continuous Mode ◽  
Layer Formation ◽  
Laser Remelting ◽  
Scan Speed ◽  
Scanning Electron

This paper reports laser remelting of crystalline Cu based alloys in order to produce amorphous layer on the surface. The as prepared Cu based master alloy ingots were imbedded in a metallic sinking with Wood metal to assure the good thermal conductivity during the laser treatment. The laser remelting of a thin surface layer and a subsequent rapid cooling of it was performed using impulse and continuous mode of Nd:YAG laser. In respectively the impulse mode the laser power and the interaction time were 1.5; 2 kW and 20÷100 ms. In the continuous mode the laser power was 2 kW, and the laser scan speed was 80÷120 mm/s. The characterization of the microstructure of surface layer was performed by XRD, scanning electron microscopy and microhardness measurements.

Laser Pulse Melting of Metals: Epitaxy and Allotropy

1980 ◽  
Vol 1 ◽  
Author(s):  
L. Buene ◽  
E. N. Kaufmann ◽  
C. M. Preece ◽  
C. W. Draper
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Layer ◽  
High Temperature ◽  
Laser Pulse ◽  
Single Crystals ◽  
Laser Power ◽  
Rutherford Backscattering ◽  
Scanning Electron ◽  
Crystallographic Orientations

ABSTRACTLaser pulse melted single crystals of several metals have been examined by the Rutherford backscattering/channeling technique and with optical and scanning electron microscopy. Metals belonging to the three major structure groups; fcc (Ni, Pd, Rh); bcc(Mo, Nb, W, Fe); and hcp (Be, Ti, Re) have been studied at various laser power levels and in different crystallographic orientations. Of these cases, Be, Ti and Fe show high temperature allotropes which are expected to influence the character of the resolidified surface layer.

scholarly journals Scanning Electron Microscopy Characterization of Aluminized Layer Formation on Ti Alloys

2006 ◽  
Vol 12 (S02) ◽  
pp. 1058-1059
Author(s):  
S Romankov ◽  
W Sha ◽  
SD Kaloshkin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Layer Formation ◽  
Ti Alloys ◽  
Microscopy Characterization ◽  
Scanning Electron Microscopy Characterization ◽  
Scanning Electron

Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2006

Effects of the Laser Power on the Microstructure and Microhardness of the Carbonitrided 45 Steel

2013 ◽  
Vol 291-294 ◽  
pp. 2613-2616
Author(s):  
Hong Mei Zhu ◽  
Ru Shu Peng ◽  
Chao Hui Weng
Keyword(s):  
Heat Treatment ◽  
Electron Microscope ◽  
Laser Power ◽  
Homogeneous Element ◽  
Element Distribution ◽  
Laser Remelting ◽  
Microstructure Morphology ◽  
The Given ◽  
Scanning Electron ◽  
Microhardness Tester

The 45 steel was processed by laser remelting after the carbonitriding heat treatment in this study. The microstructure morphology and microhardness of the laser-remelting layer at different laser powers were investigated by scanning electron microscope (SEM) and microhardness tester, respectively. The results show that a compact microstructure and a homogeneous element distribution can be achieved at the laser power of 1.2 kW under the given other laser parameters, and the microhardness was enhanced greatly.

Preparation and Characterization of Plasma-Sprayed and Laser-Remelted Ni60/Ni-WC Coatings

2014 ◽  
Vol 540 ◽  
pp. 17-20
Author(s):  
Dong Sheng Wang
Keyword(s):  
Laser Power ◽  
Composite Coatings ◽  
Microstructural Characterization ◽  
Matrix Alloy ◽  
Laser Remelting ◽  
Base Matrix ◽  
High Microhardness ◽  
Sprayed Coating ◽  
Plasma Sprayed

In this study, Ni60/Ni-WC composite coatings were first prepared by plasma spraying. Then, the coatings were remelted successively with a CO2 laser. The influences of laser power on the microstructural characterization and microhardness of the coatings were investigated. The results show that the defects of as-sprayed coating like lamellar stacking microstructure and pores were eliminated by laser remelting, and the remelted coating possessed a denser microstructure. With the increase of the laser power, the burning loss and dissolve of the WC particles is increased, while the dilution rate of the coating becomes large. The laser-remelted samples had higher hardness than the as-sprayed one. Laser power has a great impact on the coating and an optimized process parameter is helpful to achieve appropriate melting of WC particles, which leads to retain a high proportion of hard phase in the coating, good combination between the WC particles and Ni-base matrix alloy, and high microhardness.

scholarly journals Microstructure and Microhardness of Ti6Al4V Alloy Treated by GTAW SiC Alloying

2012 ◽  
Vol 12 (2) ◽  
pp. 261-266 ◽  
Author(s):  
W. Bochnowski
Keyword(s):  
Surface Layer ◽  
Arc Welding ◽  
Electric Arc ◽  
Ti6al4v Alloy ◽  
Ti6al4v Titanium Alloy ◽  
Conventional Heat Treatment ◽  
Crystalline Fracture ◽  
Scan Speed ◽  
Electric Arc Welding ◽  
Scanning Electron

Microstructure and Microhardness of Ti6Al4V Alloy Treated by GTAW SiC Alloying In this work, the change of the structure and microhardness of Ti6Al4V titanium alloy after remelting and remelting with SiC alloing by electric arc welding (GTAW method) was studied. The current intensity equal 100 A and fixed scan speed rate equal 0,2 m/min has been used to remelting surface of the alloy. Change of structure were investigated by optical and scanning electron microscopy. Microhardness test showed, that the remelting of the surface does not change the hardness of the alloy. Treated by GTAW SiC alloying leads to the formation of hard (570 HV0, 1) surface layer with a thickness of 2 mm. The resulting surface layer is characterized by diverse morphology alloyed zone. The fracture of alloy after conventional heat treatment, similarly to fracture after remelting with GTAW is characterized by extremely fine dimples of plastic deformation. In the alloyed specimens the intergranular and crystalline fracture was identified.

scholarly journals Microstructural Evolution and Hardness of Rapidly Solidified Hypereutectic Al-Si Surface Layers Produced by Laser Remelting

2021 ◽  
Author(s):  
Jaafar Abboud ◽  
Metin Kayitmazbatir ◽  
Amit Misra ◽  
Jyoti Mazumder
Keyword(s):  
Laser Power ◽  
Laser Remelting ◽  
Surface Layers ◽  
Primary Si ◽  
Maximum Value ◽  
Transmission Electron ◽  
Rapid Solidification Technique ◽  
Eutectic Si ◽  
Scan Speed ◽  
Rapidly Solidified

Abstract A laser rapid solidification technique was employed to remelt and refine the microstructure of Al-25wt.%Si and Al-30wt.%Si alloyed layers produced by laser melting. The microstructure of the as-fabricated Al-Si layers consisted of irregular polygonal primary Si crystals of size 5 to 7 µm, fine α-Al dendrites, and Al-Si eutectic. Laser rapid remelting results showed a significant refinement of all the solidified phases with increasing scan speed and decreasing laser power. At the lowest laser power (800W), the sizes of the primary Si crystals were reduced to a sub-micron level and an interwoven network of nano-sized eutectic colonies was obtained. The higher cooling rates, resulted in a reduction in the amount of the α-Al phase especially those surrounding the primary Si, thereby stimulating the eutectic Si fibers to grow from the pre-existing primary Si crystals and increased the proportion of the fibrous eutectic. Transmission electron microscopy revealed fibrous eutectic, which was internally nano-twinned, with a diameter approaching as low as 10-15 nm for the highest cooling rate. The hardness measured by nanoindentation of the eutectic in the remelted Al-25wt.%Si layer increased with decreasing the eutectic spacing (ʎ) reaching a maximum value of 3.15GPa.

scholarly journals Influence of Laser Colour Marking on the Corrosion Properties of Low Alloyed Ti

Coatings ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 375 ◽  
Author(s):  
Tadeja Kosec ◽  
Andraž Legat ◽  
Janez Kovač ◽  
Damjan Klobčar
Keyword(s):  
Electron Microscopy ◽  
Surface Layer ◽  
Photoelectron Spectroscopy ◽  
Laser Power ◽  
Chemical Structure ◽  
Laser Light ◽  
Corrosive Environment ◽  
Corrosion Properties ◽  
X Ray ◽  
Scanning Electron

In the field of surface treatment, laser colour marking can be used to produce coloured marks on the surfaces of metals. Laser colour markings can be applied to various materials, but on titanium alloys a wide spectra of vivid colours can be achieved. This study presents an analysis of the corrosion properties of laser treated surfaces that were exposed to aggressive environments. Different samples were prepared with laser light of various power intensities and processing speeds. The samples were prepared on low alloyed Ti. Electrochemical, spectroscopic and microstructural analyses were conducted in order to study the properties of the laser treated surfaces. Corrosion testing showed different effects of laser power and production speed on the properties of the laser treated surfaces. It was shown that a high intensity and slow processing rate affect the surfaces by forming oxides that are relatively stable in a corrosive environment of 0.1 M NaCl. Spectroscopic investigations including scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analyses showed the differences in chemical structure of the surface layer formed after laser treatment. Similarly, microstructural investigations showed different effects on the surface and sub-surface layer of the laser treated samples.

Development of Amorphous and Microstructured Surface Layer by Laser Surface Treatment

2013 ◽  
Vol 752 ◽  
pp. 175-182 ◽  
Author(s):  
Mária Svéda ◽  
András Roósz
Keyword(s):  
Surface Layer ◽  
Surface Treatment ◽  
Amorphous Layer ◽  
Laser Surface ◽  
Laser Remelting ◽  
X Ray Diffraction ◽  
Laser Surface Treatment ◽  
Microstructured Surface ◽  
Treatment Techniques ◽  
Laser Surface Remelting

The aim of the research was to develop an amorphous and microstructured layer on non-amorphous alloys by laser surface treatment. The as-prepared Cu based master alloy ingots were imbedded in a metallic sinking with Wood metal to assure the good thermal conductivity during the laser treatment. The laser remelting, alloying and coating techniques were applied from the laser surface treatment techniques. The surface layer production and a subsequent rapid cooling were performed using CO2 laser and pulse and continuous modes of Nd:YAG laser. The characterization of the microstructure of the resulting surface layer was investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Actual remelting on substrates showed that the process of laser remelting is a suitable technique for production of metallic glasses as surface layers. The amorphous layer up to 250 m in depth can be produced by laser surface remelting on Cu46Zr42Al7Y5 alloy.

scholarly journals An Automatic on Top Analysis of Single Scan Tracks to Evaluate the Laser Powder Bed Fusion Building Parameters

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5171
Author(s):  
Alessandra Martucci ◽  
Fabrizio Marinucci ◽  
Antonio Sivo ◽  
Alberta Aversa ◽  
Diego Manfredi ◽  
...  
Keyword(s):  
Open Source Software ◽  
Laser Power ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Computer Aided ◽  
Scan Speed ◽  
Definition Of ◽  
Fine Tune

The production of dense samples produced by laser powder bed fusion (LPBF) is mainly determined by the choice of the best combination of construction parameters. Parameter optimization is the first step in the definition of an LPBF process for new alloys or systems. With this goal, much research uses the single scan track (SST) approach for a preliminary parameter screening. This study investigates the definition of a computer-aided method by using an automatic on top analysis for the characterization of SSTs, with the aim of finding ranges of laser power and scan speed values for massive production. An innovative algorithm was implemented to discard non-continuous scans and to measure the SSTs quality using three regularity indexes. Only open source software were used to fine tune this approach. The obtained results on Al4Cu and AlSi10Mg realized with two different commercial systems suggest that it is possible to use this method to easily narrow the process parameter window that allows the production of dense samples.

Sign in / Sign up

Export Citation Format

Share Document