Laser Heat Treatment of Cast Irons—Optimization of Process Variables: Part I

1985 ◽  
Vol 107 (3) ◽  
pp. 200-207 ◽  
Author(s):  
A. K. Mathur ◽  
P. A. Molian
Keyword(s):  
Heat Treatment ◽  
Gray Iron ◽  
Case Depth ◽  
Laser Heat Treatment ◽  
Process Variables ◽  
Cast Irons ◽  
Maximum Coverage ◽  
Laser Heat ◽  
Ring Mode ◽  
Better Than

A 1.2 kw CO2-CW laser operating in ring and Gaussian beam modes was used to surface harden gray and ductile cast irons. The microstructure, case depth, hardness, surface integrity, and distortion were studied as functions of process variables (i.e., laser power, focusing optics, beam size, scan rate and thickness of the specimen). The results indicate that the ring mode is preferred over Gaussian whereas ductile iron response to laser heat treatment is better than gray iron. The maximum case depth achieved with minimum melting was 0.38 mm, and the maximum coverage rate obtained was 322.58 mm2/s.

Optimization of the Case Depth of a Cylinder Made With 4340 Steel by a Control of the Laser Heat Treatment Parameters

2018 ◽  
Author(s):  
Rachid Fakir ◽  
Noureddine Barka ◽  
Jean Brousseau
Keyword(s):  
Heat Treatment ◽  
Numerical Model ◽  
Surface Temperature ◽  
Laser Power ◽  
Case Depth ◽  
Maximum Temperature ◽  
Laser Heat Treatment ◽  
Laser Heat ◽  
4340 Steel ◽  
Cylindrical Workpiece

This paper presents a numerical model able to control the temperature distribution along a 4340 steel cylinder heat-treated with Nd: YAG laser. The numerical model developed using the numerical finite element method, was based on a study of surface temperature variation and the adjustment of this temperature by a control of the heat treatment laser power. The proposed analytical approach was built gradually by (i) the development of a numerical model of laser heat treatment of the cylindrical workpiece, (ii) an analysis of the results of simulations and experimental tests, (iii) development of a laser power adjustment approach, and (iv) proposal of a laser power control predictor using neural networks. This approach was made possible by highlighting the influence of the fixed (non-variable) parameters of the laser heat treatment on the case depth, and has shown that it is possible by controlling the laser parameters to homogenize the distribution of the maximum temperature reached on the surface for a uniform case depth. The feasibility and effectiveness of the proposed approach leads to a reliable and accurate model able to guarantee a uniform surface temperature and a regular case depth for a cylindrical workpiece of a length of 50-mm and with a diameter of between 16-mm and 22-mm.

Servo-Control Applied to the Parameters of the Laser Hardening Process for a Regular Case Depth of 4340 Steel Cylindrical Specimen

2019 ◽  
Vol 19 (3) ◽  
Author(s):  
Rachid Fakir ◽  
Noureddine Barka ◽  
Jean Brousseau
Keyword(s):  
Heat Treatment ◽  
Numerical Model ◽  
Surface Temperature ◽  
Laser Power ◽  
Case Depth ◽  
Laser Heat Treatment ◽  
Regular Case ◽  
Laser Heat ◽  
4340 Steel ◽  
Cylindrical Workpiece

This paper presents a numerical model able to control the temperature distribution along a 4340 steel cylinder heat-treated with laser. The numerical model developed using the numerical finite element method (FEM) was based on a study of surface temperature variation and the adjustment of this temperature by a control of the heat treatment laser power. The proposed analytical approach was built gradually by (i) the development of a numerical model of laser heat treatment of the cylindrical workpiece, (ii) an analysis of the results of simulations and experimental tests, (iii) development of a laser power adjustment approach, and (iv) proposal of a laser power control predictor using neural networks. This approach was made possible by highlighting the influence of the fixed (nonvariable) parameters of the laser heat treatment on the case depth and has shown that it is possible by controlling the laser parameters to homogenize the distribution of the maximum temperature reached on the surface for a uniform case depth. The feasibility and effectiveness of the proposed approach lead to a reliable and accurate model able to guarantee a uniform surface temperature and a regular case depth for a cylindrical workpiece of a length of 50 mm and with a diameter of between 16 and 22 mm.

Sub-millisecond post exposure bake of chemically amplified resists by CO 2 laser heat treatment

2010 ◽  
Author(s):  
Byungki Jung ◽  
Jing Sha ◽  
Florencia Paredes ◽  
Christopher K. Ober ◽  
Michael O. Thompson ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Laser Heat Treatment ◽  
Post Exposure ◽  
Chemically Amplified ◽  
Laser Heat ◽  
Post Exposure Bake ◽  
Chemically Amplified Resists

The preparation and performance of grain size gradient TWIP steel fabricated by laser heat treatment

2019 ◽  
Vol 743 ◽  
pp. 294-300 ◽  
Author(s):  
Kun Wang ◽  
Aiping Wei ◽  
Zimu Shi ◽  
Xizhang Chen ◽  
Jixing Lin ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Twip Steel ◽  
Laser Heat Treatment ◽  
Laser Heat ◽  
And Performance ◽  
Size Gradient

scholarly journals Effect of Laser Heat Treatment on the Microstructure and Properties of Alloy 800H

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 379 ◽  
Author(s):  
Wei Zhang ◽  
Tao Jiang ◽  
Jing Li ◽  
Liqiang Liu
Keyword(s):  
Heat Treatment ◽  
Treatment Process ◽  
Fracture Morphology ◽  
Elemental Content ◽  
Laser Heat Treatment ◽  
Alloy 800H ◽  
X Ray ◽  
Microstructure And Properties ◽  
Fracture Specimen ◽  
Laser Heat

The effects of laser heat treatment on the microstructure and properties of alloy 800H were investigated. The fracture morphology, elemental changes, and phase composition of the specimens were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffractometry (XRD). The results show that the long-lasting life of the specimen after laser heat treatment increased by 28.6%, and the elongation after fracture increased by 20.7%. The macroscopic morphology of the fracture specimen exhibited obvious ductile fracture morphology, and the changes in the elemental content and grain size significantly affected the ductility and toughness of the alloy. This study has certain guiding significance for the optimization of the heat treatment process of this type of alloy.

scholarly journals Increasing the resistance of a NiCrBSi coating to heat wear by means of combined laser heat treatment

2018 ◽  
Author(s):  
A. V. Makarov ◽  
N. N. Soboleva ◽  
M. S. Gibzun ◽  
I. Yu. Malygina ◽  
Yu. S. Korobov
Keyword(s):  
Heat Treatment ◽  
Laser Heat Treatment ◽  
Laser Heat ◽  
Nicrbsi Coating
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