Improved oxygen diffusion and overall surface characteristics using combined laser surface texturing and heat treatment process of Ti6Al4V

2022 ◽  
Vol 429 ◽  
pp. 127976
Author(s):  
V. Kashyap ◽  
P. Ramkumar
Author(s):  
Mike Mosbacher ◽  
Markus Holzinger ◽  
Mathias Galetz ◽  
Uwe Glatzel

AbstractOxidized zirconium alloys can appear as black, white and all gray shades depending on the heat treatment process. The black color results from a high amount of oxygen vacancies in non-stoichiometric zirconia (ZrO2−x) that effectively reduces the band gap of the material. In this work we compare the surface properties of black and white zirconia on ZrNb7 substrate. An oxidation in air at 600 °C for 1 h results in a dark-gray oxide with only a few micro cracks. Oxidation at low oxygen partial pressure at 600 °C for 8 h (pO2 = 10–19 Pa) generates a dense, totally black oxide scale. A three step heat treatment process, that was introduced for better coating adhesion, results in a white oxide layer with many micro cracks parallel to the surface. From the results of various microscopy and spectroscopy techniques, we derive a model of the layer formation of zirconia on ZrNb7 and give reason why black zirconia, and therefore the oxidation at low oxygen partial pressure, is favorable for tribological applications (e.g., artificial joint replacements).


Author(s):  
K. Prashanthi ◽  
B. Ramakrishna

Laser hardening is a surface heat treatment process used to enhance tribological and mechanical properties of metals which also leads to increase in service life of the components. Material removal, wear and tear, load concentration occurs mostly at rotating and reciprocating parts. Hence it is sufficient to enhance the hardness of a component at functional areas rather than the entire component. Laser hardening process is designed to change the microstructure of metals through controlled heating and cooling to get a modified surface. The constraints of traditional surface heat treatment process such as inability to treat specific area, distortion, poor degree of controllability, requirement of a quenching medium, long cycle time can be overcome by using Laser surface heat treatment and in addition to that it can be automated. With its benefits Laser surface hardening turns out to be a cost effective and energy saving process. The presented work is an investigation of the laser surface hardening via experimental results making use of a 6 axis robotic arm and a 10KW high power diode laser system as heat source with a wavelength of 980nm on leading automotive parts such as retainer, hub, and turbine blade whose materials being non-malleable cast iron, carbon steel, X20Cr13 respectively. Process parameters such as laser power from power source, scan speed were varied to understand the influence on resulting heat treated surface and efforts were made to optimize the process parameters to attain maximum hardness for the component to enhance its working life.


2008 ◽  
Vol 3 (2) ◽  
pp. 63-69
Author(s):  
M. Sivapragash ◽  
◽  
V. Sateeshkumar ◽  
P.R. Lakshminarayanan ◽  
R. Karthikeyan ◽  
...  

Author(s):  
Karanbir Singh ◽  
Aditya Chhabra ◽  
Vaibhav Kapoor ◽  
Vaibhav Kapoor

This study is conducted to analyze the effect on the Hardness and Micro Structural Behaviour of three Sample Grades of Tool Steel i.e. EN-31, EN-8, and D3 after Heat Treatment Processes Such As Annealing, Normalizing, and Hardening and Tempering. The purpose of Selecting Tool Steel is Because Tool Steel is Mostly Used in the Manufacturing Industry.This study is based upon the empirical study which means it is derived from experiment and observation rather than theory.


Friction ◽  
2021 ◽  
Author(s):  
Chia-Jui Hsu ◽  
Andreas Stratmann ◽  
Simon Medina ◽  
Georg Jacobs ◽  
Frank Mücklich ◽  
...  

AbstractLaser surface texturing (LST) has been proven to improve the tribological performance of machine elements. The micro-scale patterns manufactured by LST may act as lubricant reservoirs, thus supplying oil when encountering insufficient lubrication. However, not many studies have investigated the use of LST in the boundary lubrication regime, likely due to concerns of higher contact stresses that can occur with the increasing surface roughness. This study aims to examine the influence of LST on the fatigue lifetime of thrust rolling bearings under boundary lubrication. A series of periodic patterns were produced on the thrust rolling bearings, using two geometrically different designs, namely cross and dimple patterns. Base oil ISO VG 100 mixed with 0.05 wt% P of zinc dialkyldithiophosphate (ZDDP) was supplied. The bearings with cross patterns reduce the wear loss by two orders of magnitude. The patterns not only retain lubricant in the textured pockets but also enhance the formation of an anti-wear tribofilm. The tribofilm generation may be improved by the higher contact stresses that occur when using the textured surface. Therefore, in contrast to the negative concerns, the ball bearings with cross patterns were instead found to increase the fatigue life by a factor of three.


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