Influence of Nanosecond Laser Processing Parameters on the Titanium Alloy Surfaces Colorization

2017 ◽  
Vol 744 ◽  
pp. 223-227 ◽  
Author(s):  
Chun Ling Li ◽  
Chang Hou Lu

Laser color marking experiments on titanium alloy substrates were carried out to investigate the impact of selected laser processing parameters on the resulting colors. The CIE L*a*b* color space was used to quantify these colors. The surface roughness of the marked color areas was measured by using a TR200 hand-held surface roughness instrument. The relationships between laser parameters and CIE L*a*b* values and surface roughness of the colors were obtained. Results clearly showed that different colors ranging from blue and gray to yellow were produced. Some colors can be obtained by different sets of parameters, while some colors can only be produced by a specific combination of process parameters due to the existence of different forms of heat input and thermal process. The b* value increased to the maximum which represented yellow then decreased. The surface roughness of color areas decreased with the increase of focal plane offset, scanning velocity, or hatch space.

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2621
Author(s):  
Aneta Bartkowska

The paper presents the results of a study of the microstructure, chemical composition, microhardness and corrosion resistance of Cr-B coatings produced on Vanadis 6 tool steel. In this study, chromium and boron were added to the steel surface using a laser alloying process. The main purpose of the study was to determine the impact of those chemical elements on surface properties. Chromium and boron as well as their mixtures were prepared in various proportions and then were applied on steel substrate in the form of precoat of 100 µm thickness. Depending on the type of precoat used and laser processing parameters, changes in microstructure and properties were observed. Coatings produced using precoat containing chromium and boron mixture were characterized by high microhardness (900 HV0.05–1300 HV0.005) while maintaining good corrosion resistance. It was also found that too low laser beam power contributed to the formation of cracks and porosity.


2012 ◽  
pp. 57-75
Author(s):  
Mohd Idris Shah Ismail ◽  
Zahari Taha ◽  
Mohd Hamdi Abdul Shukor

In this paper, the experimental design by using the Taguchi method was employed to optimize the processing parameters in the plasma arc surface hardening process. The evaluated processing parameters are arc current, scanning velocity and carbon content of steel. In addition, the significant effects of the relation between processing parameters were also investigated. An orthogonal array, signal-to-noise (S/N) ratio and analysis of variance (ANOVA) were employed to investigate the effects of these processing parameters. Through this study, not only the increasing in hardened depth and improvement in surface roughness, but the parameters that significantly affect on the hardening performance were also identified. Experimental results showed the effectiveness of this approach. Dalam kertas kerja ini, reka bentuk ujikaji menggunakan kaedah Taguchi digunakan untuk mengoptimumkan parameter pemprosesan dalam proses arka plasma pengerasan permukaan. Parameter pemprosesan yang dinilai adalah arus arka, halaju imbasan dan kandungan karbon dalam keluli. Sebagai tambahan, kesan-kesan penting yang lain seperti hubungan di antara parameter pemprosesan juga diselidiki. Tatasusunan ortogon, nisbah signal to noise (S/N) dan analisis varians (ANOVA) digunakan untuk mengkaji kesan parameter pemprosesan ini. Melalui kajian ini, bukan sahaja kedalaman pengerasan bertambah dan kekasaran permukaan lebih baik, malah parameter pemprosesan yang nyata sekali menpengaruhi prestasi pengerasan dikenal pasti. Hasil percubaan mengesahkan keberkesanan pendekatan ini.


2008 ◽  
Vol 368-372 ◽  
pp. 1203-1205 ◽  
Author(s):  
Min Zheng ◽  
Ding Fan ◽  
Xiu Kun Li ◽  
Qi Bin Liu ◽  
Wen Fei Li ◽  
...  

Based on a high power CO2 laser beam passing by pyramid polygon mirror, the bioceramic coatings of gradient composition were fabricated on titanium alloy substrate (Ti-6Al-4V). The relations among laser processing parameters, microstructure and biocompatibility of the gradient bioceramic coatings were investigated. The results indicated that the contents of rare earth oxide additions had an immediate effect on the formation of bioactive phases. The gradient bioceramic coatings showed favorable biocompatibility in vivo after they were implanted into canine femur for 45, 90, and 180 days, respectively. The bioceramic coatings of Ca/P=1.4 and 0.6wt.% Y2O3 totally combined with new bones merely implanted for 45 days. Furthermore, the MTT (Methyl Thiazolyl Tetrazolium) colorimetry results of cell proliferation demonstrated that the cell growth distinctly increased on the gradient bioceramic coatings by laser cladding compared with the un-treated titanium alloy substrate.


2012 ◽  
Vol 472-475 ◽  
pp. 2476-2479 ◽  
Author(s):  
Gen Fu Yuan ◽  
Wei Zheng ◽  
Xue Hui Chen

An experimental device of KOH solutions jet-assisted laser etching is designed, Laser-chemical combined etching technology is combined with the Medium-jet erosion processing ,and the influence on the etching capacity and cross section quality of material sample of laser processing parameters,jet processing parameters are studied. The results show that the laser processing parameters and jet processing have a decisive impact on the quality of the workpiece, the composite processing technology can remove most of melting slag which are produced by the laser processing, the surface roughness are effectively reduced. The blind holes of the machined materials have the regular shape.


2013 ◽  
Vol 834-836 ◽  
pp. 872-875 ◽  
Author(s):  
Qun Qin ◽  
Guang Xia Chen

The primary goal of this research is the effects of laser process parameters on surface roughness of metal parts built by selective laser melting. The main processing parameters used to control the surface roughness of melted layers are laser power, scanning velocity and overlap ratio. In our work, an orthogonal experimental design was employed to find the changing rules of the surface roughness through changing SLM processing parameters. The results show that the overlap ratio is the most important factor to affect the surface roughness. When the overlap ratio is below 50%, the surface roughness value of melted layers will decrease with laser power density increasing. When the overlap ratio is higher than or equal to 50%, the surface roughness value increases with the laser power density increasing. The optimal parameters of laser power 143W, scanning velocity 5m/min and overlap ratio 30% can be used to achieve melted layers with the best surface quality in our experiments, and the roughness value increases with slicing thickness increasing and the surface bias angle decreases.


2021 ◽  
Author(s):  
Ying Wei ◽  
Xiaolong Fang ◽  
Ningsong Qu ◽  
Di Zhu

Abstract TB2 titanium alloys are widely used in the aerospace industry. A high surface quality is required for the performance and fatigue life of titanium alloy parts. Electropolishing is useful for thin metal plates owing to its good processability and conformability. In this study, electrolyte flushing was proposed for electropolishing a large surface and a NaCl-containing ethylene glycol electrolyte was adopted. Three different mechanical grindings were employed for pretreatment, and the ideal surface quality was obtained with a rubber grinding head. Therefore, in the process of electropolishing a large surface, electrolyte flushing is superior to stirring because its flow field is even and controllable. The effects of the main processing parameters (voltage, flow rate, and process time) on the surface roughness and morphology were studied. Finally, a mirror-like surface with a surface roughness of 10.5 nm was obtained after flushing electropolishing for 30 min under a voltage of 25 V and a flow rate of 0.84 m/s.


2016 ◽  
Vol 1136 ◽  
pp. 406-411
Author(s):  
Jian Zhao ◽  
Zhan Qiang Liu

The purpose of the paper is to investigate the influence of the processing parameters on the surface roughness in rotary ultrasonic burnishing of titanium alloy Ti-6Al-4V plane. A Taguchi orthogonal array for three levels and four factors, which include burnishing depth, feed fate, spindle speed and ultrasonic frequency, are designed. The optimal combination of ultrasonic burnishing process parameters is obtained. Analysis of variance (ANOVA) is applied to determine the most significant processing parameter and to obtain the optimal combination level of processing parameters for the lowest surface roughness. The results show that burnishing depth has the most predominant effect on surface roughness, and spindle speed is the secondary one. Feed rate and ultrasonic frequency are then followed and have no distinct effect on surface roughness in rotary burnishing of Ti-6Al-4V.


2019 ◽  
Vol 298 ◽  
pp. 00051 ◽  
Author(s):  
Ivan Ushakov ◽  
Yuri Simonov

The alterations in the microhardness of a titanium alloy Ti85.85Al6.5Zr4Sn2Nb1Mo0.5Si0.15 subjected to laser treatment were investigated. Laser processing consists of a series of pulses with durations 20 ns. We used various methods of laser processing, which differed in power density, wavelength, geometrical pattern of irradiation and so on. The dependences of the microhardness on the load on the indenter were found. The laser processing modes providing the increased microhardness are determined. The investigations were carried out at loads from 0.49 N to 4.9 N, with maximum indentation depth of the Vickers pyramid up to 12 μm. Vickers microhardness can be increased by 20 – 40 %. At the same time, the plastic properties of the hardened layer are improved. The probability of crack formation during indentation of the initial alloy increased with a load on the indenter and reached 0.52 for a load of 4.9 N. In two of the treated areas of the three presented, crack formation was not recorded at any load. The mechanisms of hardening of the material surface layer under the influence of a laser pulse are discussed. Using the methods of computational mathematics, the character of sample heating under the influence of a single laser pulse is determined. The perspectives for the development of the proposed processing method are permitting to obtain the optimal mechanical properties of the hardened layer are discussed.


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