Improved Method of CO2 Laser Cutting of Aluminum Nitride

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Raathai Molian ◽  
Pranav Shrotriya ◽  
Pal Molian

The traditional “evaporation∕melt and blow” mechanism of CO2 laser cutting of aluminum nitride (AlN) chip carriers and heat sinks suffers from energy losses due to its high thermal conductivity, formation of dross, decomposition to aluminum, and uncontrolled thermal cracking. In order to overcome these limitations, a thermochemical method that uses a defocused laser beam to melt a thin layer of AlN surface in oxygen environment was utilized. Subsequent solidification of the melt layer generated shrinkage and thermal gradient stresses that, in turn, created a crack along the middle path of laser beam and caused material separation through unstable crack propagation. The benefits associated with thermal stress fracture method over the traditional method are improved cut quality, higher cutting speed, and lower energy losses.

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3839
Author(s):  
Ray Tahir Mushtaq ◽  
Yanen Wang ◽  
Mudassar Rehman ◽  
Aqib Mashood Khan ◽  
Mozammel Mia

Carbon dioxide (CO2) laser cutting finds one of its most relevant applications in the processing of a wide variety of polymeric materials like thermoplastics and thermosetting plastics. Different types of polymeric materials like polypropylene (PP), polymethyl methacrylate (PMMA), low- and high-density polyethylene (LDPE, HDPE), are processed by laser for different household as well as commercial products in the industry. The reason is their easy availability and economical aspect in the market. The problems associated with laser cutting include heat-affected zone (HAZ) generated on the cut surface, kerf width (KW), surface roughness (SR), dross formation, and striations formation. Furthermore, other related problems include taper cutting for deep parts and high-power consumption. The primary purpose of this work is a comprehensive literature review in CO2 laser cutting of polymeric materials. The influence of parametric variation on the cut quality is also explained. Cut quality in terms of KW, SR, HAZ, dross formation, and striations formation is analyzed by optimizing cutting variables like laser power (PL), cutting speed (CS), assist gas pressure (Pg), pulse frequency, nozzle type and its diameter, and stand-off distance (SOD). The effects of the laser cutting on the properties of different thermoplastics/thermosetting materials are also reported. However, this topic requires further studies on exploring the range of polymeric materials, and their optimal parameters selection to improve the cut quality. Therefore, the research gaps and future research directions are also highlighted in the context of CO2 laser cutting for polymeric materials.


2015 ◽  
Vol 88 (1) ◽  
pp. 125-137 ◽  
Author(s):  
Shib Shankar Banerjee ◽  
Anil K. Bhowmick

ABSTRACT The application of the low-power CO2 laser-cutting process to fluoroelastomer (FKM), polyamide 6 (PA6), PA6/FKM thermoplastic elastomers (TPEs), and their thermoplastic vulcanizate (TPV) is reported. The main laser process parameters studied were laser power, cutting speed, and material thickness. The value of the top and bottom widths of the slit that were formed during laser cutting (kerf width), melted transverse area, and melted volume per unit time were measured and analyzed. Interestingly, TPE showed a smaller melted area and melted volume per unit time when compared with those values with PA6. Dynamic vulcanization further decreased these values. For example, the melted areas of PA6 and TPE were 510 × 10−3 mm2 and 305 × 10−3 mm2, respectively, which reduced to 238 × 10−3 mm2 for TPV at 40 W laser power. FKM showed the lowest value (melted area of 180 × 10−3 mm2). In addition, the output quality of the cut surface was examined by measuring the root mean square (RMS) roughness of the cut edges and heat-affected zone (HAZ). The obtained results indicated that the dimension of the HAZ and RMS roughness largely decreased in TPE when compared with PA6. For example, the HAZ of PA6 was 700 μm, which decreased to 230 μm for TPE at 40 W laser power. On the other hand, HAZ was nonexistent for FKM. Infrared spectroscopic analysis showed that there was no structural change of TPE or pristine polymers after applying the low-power CO2 laser on the surface of materials. CO2 laser cutting will be a new technique in this industry, and this analysis will assist the manufacturing industry to choose a suitable laser system with exhaustive information of process parameters for cutting or machining of rubber, TPEs, and TPVs.


Author(s):  
Miloš Madić ◽  
Mohamed H Gadallah ◽  
Dušan Petković

For an efficient use of laser cutting technology, it is of great importance to analyze the impact of process parameters on different performance indicators, such as cut quality criteria, productivity criteria, costs as well as environmental performance criteria (energy and resource efficiency). Having this in mind, this study presents the experimental results of CO2 laser fusion cutting of AISI 304 stainless steel using nitrogen, with the aim of developing a semi-empirical mathematical model for the estimation of process efficiency as an important indicator of the achievable energy transfer efficiency in the cutting process. The model was developed by relating the theoretical power needed to melt the volume per unit time and used laser power, where the change of kerf width was modeled using an empirical power model in terms of laser cutting parameters such as laser power, cutting speed, and focus position. The obtained results indicated the dominant effect of the focus position on the change in process efficiency, followed by the cutting speed and laser power. In addition, in order to maximize process efficiency and simultaneously ensure high cut quality without dross formation, a laser cutting optimization problem with constraints was formulated and solved. Also, a multi-objective optimization problem aimed at simultaneous optimization of process efficiency and material removal rate was formulated and solved, where the determined set of Pareto non-dominated solutions was analyzed by using the entropy method and multi-criteria decision analysis method, that is, the Technique for Order of Preference by Similarity to Ideal Solution. The optimization results revealed that in order to enhance process efficiency and material removal rate, while ensuring high cut quality without dross formation, focusing the laser beam deep into the bulk of material is needed with particular trade-offs between laser power and cutting speed levels at high pressure levels of nitrogen.


2008 ◽  
Vol 5 (8) ◽  
pp. 990-996 ◽  
Author(s):  
Nukman Yusoff ◽  
Saiful Rizal Ismail ◽  
Azuddin Mamat ◽  
Aznijar Ahmad-Yazi

2016 ◽  
Vol 78 (7) ◽  
Author(s):  
Abdul Fattah Mohamad Tahir ◽  
Ahmad Razelan Rashid

Development of new material known as Ultra High Strength Steel (UHSS) able to improve the vehicle mass thus reflecting better fuel consumption. Transformation into high strength steel has been a significant drawback in trimming the UHSS into its final shape thus laser cutting process appeared to be the solution. This study emphasizes the relationship between Carbon Dioxide (CO2) laser cutting input parameters on 22MnB5 boron steel focusing on the kerf width formation and Heat Affected Zone (HAZ). Experimental research with variation of laser power, cutting speed and assisted gas pressure were executed to evaluate the responses. Metrological and metallographic evaluation of the responses were made on the outputs that are the kerf width formation and HAZ.  Positive correlation for power and negative interaction for cutting speed were found as the major factors on formation of the kerf. For the HAZ formation, thicker HAZ were formed as bigger laser power were applied to the material. Cutting speed and gas pressure does not greatly influence the HAZ formation for 22MnB5 boron steel.


2017 ◽  
Vol 756 ◽  
pp. 71-79
Author(s):  
Martin Lachman ◽  
Jiří Šafka

Laser technologies are considered to be unconventional technologies. Laser cutting is one of the most popular industrial operations that use a laser beam. Fibre lasers are most commonly used for cutting metallic materials. The aim of this paper is to experimentally demonstrate a procedure for determining the focal length of a laser beam from the output of the cutting head of a JK400FL fibre laser. Along with other factors, the correct position of the focal point of a laser beam cutting materials, plays a vital role in the quality of the cut and also in determining the cutting speed. It is possible to use a higher cutting speed of the laser machine, without compromising the quality of the cut.


Author(s):  
Lyubomir Lazov ◽  
Pavels Narica ◽  
Janis Valiniks ◽  
Antons Pacejs ◽  
Hristina Deneva ◽  
...  

By taking advantage of the best characteristics of wood, modern production methods can offer hard wearing and ecological solutions in industrial construction, house building, machinery construction, furniture manufacturing, transport and many other industries. Laser cutting process is an alternative choice to prepare the final shape of wood parts. Materials like wood have good laser light absorption of wavelength 10600 nm. In this paper a CO2 laser system with a maximum continuous-wave output power of 150 W is described and used in studying laser cutting process of wood materials. Cut depth is evaluated with variation of values of laser power and cutting speed. Additionally, optimal values of parameters for laser cutting of different wood plate thicknesses are determined and graphs are created showing the results.


2019 ◽  
Vol 44 (1) ◽  
pp. 21-27
Author(s):  
Dobre Runchev ◽  
Filip Zdraveski ◽  
Irena Ivanova

The main objective of the research covered in this paper is to present results for the quality of surfaces thermally cut with a laser beam. The variety of steel materials used as samples on which laser cutting is performed are the following Č.0146 (1.0330), Č.0147 (1.0333), Č.2131 (1.5024), SS Ferbec CR, HARDOX 450 and HARDOX 550. Thermal cutting is carried out with a CNC controlled Fiber laser BAYKAL type BLS–F–1530. The quality of the cut surface is analyzed based on varying the power of the laser beam, changing cutting speed and the type of additional gas (oxygen, air and nitrogen). By visual inspection, measuring the roughness of the cut surface and measuring the width of the intersection, it is determined the influence of the factors like type of the base material, type of gases, the power of thelaser beam and the cutting speed, in accordance with the standards DIN EN ISO 9013-2002 and the JUS C.T3.022.


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