A study on the effect of molten pool thermal history and gaseous environment in laser surface alloying of AISI 1020 steel with TiN

Optik ◽  
2021 ◽  
pp. 167758
Author(s):  
P N V Gopala Krishna ◽  
Vijayababu Vommi ◽  
Amit Choudhary ◽  
Muvvala Gopinath
Keyword(s):  
Thermal History ◽  
Molten Pool ◽  
Laser Surface ◽  
Surface Alloying ◽  
Laser Surface Alloying ◽  
Gaseous Environment

Modelling of Turbulent Transport in Laser Surface Alloying

2003 ◽  
Author(s):  
Nilanjan Chakraborty ◽  
Dipankar Chatterjee ◽  
Suman Chakraborty
Keyword(s):  
Phase Change ◽  
Thermal History ◽  
Molten Pool ◽  
Turbulent Transport ◽  
Laser Surface ◽  
Work Piece ◽  
Surface Alloying ◽  
Three Dimensional Model ◽  
Entire Cross Section ◽  
Laser Surface Alloying

In this paper, we present a modified k-ε model capable of addressing turbulent molten metal-pool convection in the presence of a continuously evolving phase-change interface during a laser surface alloying process. The phase change aspects of the present problem are addressed using a modified enthalpy-porosity technique. The k-ε model is suitably modified to account for the morphology of the solid-liquid interface. A mathematical model is subsequently utilized to simulate a typical laser alloying process with high power, where effects of turbulent transport can actually be realized. The three-dimensional model is able to predict the species concentration distribution inside the molten pool during alloying, as well as in the entire cross section of the solidified alloy. In order to investigate these effects, the turbulent simulation results are compared with those with laminar transport for same problem parameters. Significant effects of turbulent transport on penetration and the geometrical features of the molten pool are observed which is an outcome of the thermal history of the pool. The thermal history in turn determines the microstructure of the work piece, which finally governs the mechanical properties of the work piece.

scholarly journals Diode Laser Surface Alloying of Armor Steel with Tungsten Carbide

2017 ◽  
Vol 62 (2) ◽  
pp. 473-481 ◽  
Author(s):  
D. Janicki ◽  
J. Górka ◽  
W. Kwaśny ◽  
K. Gołombek ◽  
M. Kondracki ◽  
...  
Keyword(s):  
Molten Pool ◽  
Structural Integrity ◽  
Laser Surface ◽  
Surface Alloying ◽  
X Ray Diffraction ◽  
Surface Layers ◽  
Laser Surface Alloying ◽  
Average Hardness ◽  
Complex Carbides ◽  
Armor Steel

AbstractMetal matrix composite (MMC) surface layers reinforced by WC were fabricated on armor steel ARMOX 500T plates via a laser surface alloying process. The microstructure of the layers was assessed by scanning electron microscopy and X-ray diffraction.The surface layers having the WC fraction up to 71 vol% and an average hardness of 1300 HV were produced. The thickness of these layers was up to 650 μm. The addition of a titanium powder in the molten pool increased the wettability of WC particles by the liquid metal in the molten pool increasing the WC fraction. Additionally, the presence of titanium resulted in the precipitation of the (Ti,W)C phase, which significantly reduced the fraction of W-rich complex carbides and improved a structural integrity of the layers.

Microstructures of Laser Processed Fe-Cr Surface Alloys

1981 ◽  
Vol 39 ◽  
pp. 328-329
Author(s):  
P. A. Molian ◽  
K. H. Khan ◽  
W. E. Wood
Keyword(s):  
Cooling Rate ◽  
Pure Iron ◽  
Continuous Wave ◽  
Laser Surface ◽  
Material Surface ◽  
Constitution Diagram ◽  
Incident Power ◽  
Surface Alloying ◽  
Laser Surface Alloying ◽  
Spot Diameter

In recent years, the effects of chromium on the transformation characteristics of pure iron and the structures produced thereby have been extensively studied as a function of cooling rate. In this paper, we present TEM observations made on specimens of Fe-10% Cr and Fe-20% Cr alloys produced through laser surface alloying process with an estimated cooling rate of 8.8 x 104°C/sec. These two chromium levels were selected in order to study their phase transformation characteristics which are dissimilar in the two cases as predicted by the constitution diagram. Pure iron (C<0.01%, Si<0.01%, Mn<0.01%, S=0.003%, P=0.008%) was electrodeposited with chromium to the thicknesses of 40 and 70μm and then vacuum degassed at 400°F to remove the hydrogen formed during electroplating. Laser surface alloying of chromium into the iron substrate was then performed employing a continuous wave CO2 laser operated at an incident power of 1200 watts. The laser beam, defocussed to a spot diameter of 0.25mm, scanned the material surface at a rate of 30mm/sec, (70 ipm).

Laser surface alloying of Al and AlSi10Mg with Ti and Ni

1998 ◽  
Author(s):  
N. Pirch ◽  
G. Backes ◽  
E. W. Kreutz ◽  
X. He ◽  
A. Weisheit ◽  
...  
Keyword(s):  
Laser Surface ◽  
Surface Alloying ◽  
Laser Surface Alloying
Sign in / Sign up

Export Citation Format

Share Document