Overflow-assisted laser machining of titanium alloy: surface characteristics and temperature field modeling

In order to research the effect of process parameters on temperature field evolution in laser remelting coating prepared by plasma spraying on titanium alloy surface，the finite element model of laser multi-tracks remelting temperature field was established based on ANSYS, and remelting temperature field was analyzed. The analysis results show that: under certain scanning velocity and laser spot diameter, too small laser power can't achieve metallurgical combination between coating and substrate; the effect on temperature field of scanning velocity was smaller than laser power; the influence on molten pool center temperature and remelting width of spot diameter is bigger; preheating coating and substrate can be effectively balance remelting process temperature field, thereby reducing the thermal stress and coating cracks appear chance.Through the calculation model can master the evolution of the temperature of lasre remelting process and can provide the theory basis for process parameter selection and optimization.

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Study on the Influence of Surface Temperature Field of Aluminum Alloy Etched by Laser Water Jet Composite Machining

Materials ◽

10.3390/ma13143206 ◽

2020 ◽

Vol 13 (14) ◽

pp. 3206

Author(s):

Xuehui Chen ◽

Xin Xu ◽

Wei Liu ◽

Lei Huang ◽

Hao Li ◽

...

Keyword(s):

Aluminum Alloy ◽

Temperature Field ◽

Surface Temperature ◽

Process Parameters ◽

Water Jet ◽

Laser Machining ◽

Material Surface ◽

Laser Etching ◽

Surface Temperature Field

This paper studies the compound effect of liquid medium and laser on the workpiece and analyses the law of material surface temperature change during the processing. Taking 7075-T6 aluminum alloy as the research object, the surface temperature field of aluminum alloy processed using water-jet-assisted laser machining under different process parameters was simulated using finite element software. In addition, the temperature field of the material surface was detected in real-time using the self-built water-jet-assisted laser machining temperature field detection system, and the processing results were observed and verified using an optical microscope, scanning electron microscope, and energy spectrum analyzer. The results show that when the water jet inflow angle is 45°, the heat-affected area of the material surface is the smallest, and the cooling effect of the temperature field of the material surface is better. Considering the liquidus melting point of 7075 aluminum alloys, it is concluded that the processing effect is better when the water jet velocity is 14 m·s−1, the laser power is 100 W, and the laser scanning speed is 1.2 mm·s−1. At this time, the quality of the tank is relatively good, there are no cracks in the bottom of the tank, and there is less slag accumulation. Compared with anhydrous laser etching, water-jet-assisted laser etching can reduce the problems of micro-cracks, molten slag, and the formation of a recast layer in laser etching and improve the quality of the workpiece, and the composition of the bottom slag does not change. This study provides theoretical guidance and application support for the selection and optimization of process parameters for water-jet-assisted laser etching of aluminum alloy and further enriches the heat transfer mechanism of multi-field coupling in the process of water-jet-assisted laser machining.

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Influence of micro-nano surface texture on the hydrophobicity and corrosion resistance of a Ti6Al4V alloy surface

Anti-Corrosion Methods and Materials ◽

10.1108/acmm-05-2021-2488 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Bochun Xu ◽

Nan Zou ◽

Yunhao Jia ◽

Chao Feng ◽

Jiajia Bu ◽

...

Keyword(s):

Corrosion Resistance ◽

Titanium Alloy ◽

Surface Texture ◽

Surface Hydrophobicity ◽

Contact Angle Measurement ◽

Angle Measurement ◽

Alloy Surface ◽

Measurement Instruments ◽

Content Type

Purpose The purpose of this paper is to study the effect of micro-nano surface texture on the corrosion resistance of a titanium alloy and investigate the correlation between corrosion resistance and hydrophobicity. Design/methodology/approach The surface of the Ti6Al4V alloy was modified by laser processing and anodizing to fabricate micro-pits, nanotubes and micro-nano surface textures. Afterward, the surface morphology, hydrophobicity and polarization curve of the samples were analyzed by cold field scanning electron microscopy, contact angle measurement instruments and a multi-channel electrochemical workstation. Findings The micro-nano surface texture can enhance the hydrophobicity of the Ti6Al4V surface, which may lead to better drag reduction to ease the friction of implants in vivo. Nevertheless, no correlation existed between surface hydrophobicity and corrosion resistance; the corrosion resistance of samples with nanotubes and high-density samples with micro-nano surface texture was extremely enhanced, indicating the similar corrosion resistance of the two. Research limitations/implications The mechanism of micro-dimples on the corrosion resistance of the micro-nano surface texture was not studied. Practical implications The density of micro-pits needs to be optimized to guarantee excellent corrosion resistance in the design of the micro-nano surface texture; otherwise, it will not fulfill the requirement of surface modification. Originality/value The influence of the micro-nano surface texture on the corrosion resistance, as well as the relationship between hydrophobicity and corrosion resistance of the titanium alloy surface, were systematically investigated for the first time. These conclusions offer new knowledge.

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Transfer of Abrasive Material at Grinding a Titanium Alloy with a Wheel of Cubic Boron Nitride

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.316.521 ◽

2021 ◽

Vol 316 ◽

pp. 521-526

Author(s):

Vladimir A. Nosenko ◽

Alexander V. Fetisov ◽

Semen P. Kuznetsov

Keyword(s):

Titanium Alloy ◽

Chemical Composition ◽

Boron Nitride ◽

Chemical Elements ◽

Cubic Boron Nitride ◽

Water Soluble ◽

Alloy Surface ◽

Ceramic Bond ◽

Abrasive Tools ◽

Wear Products

The article summarizes the results of the of the titanium alloy surface morphology and chemical composition study after grinding with a wheel of cubic boron nitride on a ceramic bond. The titanium alloy was treated using the method of cut-in grinding in the finishing mode using a synthetic water-soluble lubricant-cooling liquid that does not contain mineral oil. The research was carried out using the FEI Versa 3D LoVac electron microscope. Digital photos of the titanium alloy surface at different magnifications are given. Individual objects’ morphology allows us to identify them as wear products of abrasive tools. The chemical composition of the selected objects was studied by local x-ray spectral analysis. CBN crystals are partially or completely pressed into the treated surface and covered with a layer of the treated material. On the surface of CBN crystals, there are chemical elements that are part of the abrasive tool bond.

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