scholarly journals Research on the Mechanism of Micro-Water Jet-Guided Laser Precision Drilling in Metal Sheet

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 343
Author(s):  
Yinuo Zhang ◽  
Hongchao Qiao ◽  
Jibin Zhao ◽  
Zhihe Cao

As the microporous structure has been widely used in the field of precision machining, at the same time, the requirements for the quality of microporous machining are continuously increasing. Water jet-guide laser processing technology (WJGL) has been gradually applied for its high machining precision. However, there are a few researches on the heat conduction process of WJGL processing metal materials. Therefore, it is of great significance to study the transient thermal effect of metal materials and the mechanism of material removal to improve the processing quality. In order to explore the heat conduction model of WJGL processing metal materials, this paper is based on the “element birth and death” technique in the finite element method, and the three-dimensional transient temperature field of four typical metal materials (titanium alloy, stainless steel, aluminum alloy, copper) and material removal model are established. Under this model, the removal mechanism of different metal materials and the influence of different process parameters on the temperature field distribution of the material are studied, and the influence of fixed-position drilling and helix drilling on the microporous morphology is compared. The results show that copper and aluminum alloys can obtain a larger depth-to-diameter ratio and a smaller hole taper. Titanium alloy and stainless steel have better hole roundness, lower hole edge temperature, and smaller thermal deformation. Hole roundness error and hole taper decrease with the increase of laser power. The roundness error of each material is reduced to within 10 μm when the laser power is 10 W, and the average hole taper is 8.73°.

2017 ◽  
Vol 749 ◽  
pp. 46-51
Author(s):  
Masahiko Sato ◽  
Akihiro Fukuma ◽  
Kanae Yamamoto ◽  
Takashi Matsuno

This study described the effect of mechanical properties on the roundness of a drilled hole in the drilling of low-rigidity workpieces. A thin-thickness part workpiece model involving a beam plate structure fixed on both ends was used in the study. The effects of feed, workpiece length, distance from the fixed end to the drilling point, and mechanical properties of the workpiece on the roundness of the hole were investigated. The thrust force increased with feed and the roundness became worse with feed. The hole was enlarged in the longitudinal direction of the workpiece at the upper section of the hole. An increase in the workpiece length decreased the rigidity of the workpiece and deteriorated the roundness of the hole. The roundness error was extremely small when the drilling point was near the fixed end. Carbon steel, aluminum alloy, stainless steel, and titanium alloy were used as workpiece materials. The thrust force in the drilling of titanium alloy and stainless steel was considerably larger than that of the carbon steel and aluminum alloy. The roundness of the hole was worse in the drilling of titanium alloy and stainless steel than that in the drilling of carbon steel and aluminum alloy. Plastic deformation occurred in the workpieces made of titanium alloy and stainless steel, which is probably because the workpiece was yielded by the large thrust force. The value of the ratio of the thrust force in drilling to the Young’s modulus of the workpiece was used in evaluating the deflection of the workpiece and the roundness error of the hole in drilling.


Author(s):  
Pavel Polák ◽  
Ján Žitňanský ◽  
Petr Dostál ◽  
Katarína Kollárová

In this article, we deal with a progressive production technology using the water jet cutting technology with the addition of abrasives for material removal. This technology is widely used in cutting various shapes, but also for the technology of machining such as turning, milling, drilling and cutting of threads. The aim of this article was to analyse the surface of selected types of metallic materials after abrasive machining, i.e. by assessing the impact of selected machining parameters on the surface roughness of metallic materials.


2012 ◽  
Vol 197 ◽  
pp. 802-807
Author(s):  
Hua Feng Guo ◽  
Tao Sun ◽  
Zhi Li ◽  
Ju Li Li

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.


Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3206
Author(s):  
Xuehui Chen ◽  
Xin Xu ◽  
Wei Liu ◽  
Lei Huang ◽  
Hao Li ◽  
...  

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.


2012 ◽  
Vol 459 ◽  
pp. 315-319 ◽  
Author(s):  
Ke Dian Wang ◽  
Wen Qiang Duan ◽  
Xue Song Mei ◽  
Wen Jun Wang

The experiments of micro-hole ablation are conducted firstly on titanium alloy Ti-6Al-4V with Nd: YAG millisecond laser. A significant factor which affects the depth of blind hole is found: the depth of recast material. This paper closely examines the regularity of recast depth varying with laser parameters, discovering that the ratio of recast depth to the entire hole depth decreases as pulse width decreases, and increases as peak power decreases. Verification experiment is conducted on stainless steel 1Cr13, eventually micro-hole with very thin recast layer is drilled when the maximum peak power and the minimum pulse width of the present millisecond laser are used.


2014 ◽  
Vol 513-517 ◽  
pp. 218-222
Author(s):  
Zheng Long Zou ◽  
Xiong Duan ◽  
Chu Wen Guo

Combining with the electron microscope analysis of the morphology of incision, the mechanism of abrasive water jet cutting metal materials was carried out to explore, for the rational selection of abrasive jet cutting parameters, to extend its application to provide the basis. Study shows that the abrasive water jet cutting metal materials, the material damage mechanism is mainly to yield deformation and failure and shear of grinding damage, grooving formation is mainly caused by falling impact deformation and furrows grinding.


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