Search results

1 – 10 of 122
Article
Publication date: 15 June 2012

Ugur Caligulu, Mustafa Taskin, Haluk Kejanli and Ayhan Orhan

The purpose of this paper is to investigate interface characterization of CO2 laser welded AISI 304 austenitic stainless steel and AISI 1010 low carbon steel couple. Laser welding

Abstract

Purpose

The purpose of this paper is to investigate interface characterization of CO2 laser welded AISI 304 austenitic stainless steel and AISI 1010 low carbon steel couple. Laser welding experiments were carried under argon and helium atmospheres at 2000, 2250 and 2500 W heat inputs and 200‐300 cm/min welding speeds.

Design/methodology/approach

The microstructures of the welded joints and the heat affected zones (HAZ) were examined by optical microscopy, SEM, EDS and X‐Ray analysis. The tensile strength of the welded joints was measured.

Findings

The result of this study indicated that the width of welding zone and HAZ became much thinner depending on the increased welding speed. On the other hand, this width widened depending on the increased heat input. Tensile strength values also confirmed this result. The best properties were observed at the specimens welded under helium atmosphere, at 2500 W heat input and at 200 cm/min welding speed.

Originality/value

There are many reports which deal with the shape and solidification structure of the fusion zone of laser beam welds in relation to different laser parameters. However, the effect of all influencing factors of laser welding has up to now not been extensively researched. Much work is required for understanding the combined effect of laser parameters on the shape and microstructure of the fusion zone. This paper, therefore, is concerned with laser power, welding speed, defocusing distance and type of shielding gas and their effects on the fusion zone shape and final solidification structure of some stainless steels.

Details

Industrial Lubrication and Tribology, vol. 64 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 June 1994

Wolfgang Kolbl

Describes the MetaTorch sensor system which uses standard componentssuch as CCD cameras, laser diodes and electronic pre‐processinghardware to determine the location of objects…

Abstract

Describes the MetaTorch sensor system which uses standard components such as CCD cameras, laser diodes and electronic pre‐processing hardware to determine the location of objects and features with the help of the structured light principle. Examines the sensor system’s four main parts: the sensor head, the data acquisition board, the software and the interface to the robot or handling machine controller. The initial application was as an arc welding tracking system but has expanded to a variety of feature detection or feature following tasks including gluing, seam sealing and car seat trimming.

Details

Industrial Robot: An International Journal, vol. 21 no. 3
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 30 May 2019

Pramod Kumar and Amar Nath Sinha

The present research work aims to study the effect of average beam power (laser process parameters) on the overlapping factor, depth of penetration (DOP), weld bead width, fusion…

Abstract

Purpose

The present research work aims to study the effect of average beam power (laser process parameters) on the overlapping factor, depth of penetration (DOP), weld bead width, fusion zone and heat affected zone (HAZ) in laser welding of 304L and st37 steel. Back side and top surface morphology of the welded joints have also been studied for varying average beam power.

Design/methodology/approach

Laser welding of austenitic stainless steel (304L) and carbon steel (st37) was carried out using Nd:YAG laser integrated with ABB IRB 1410 robot in pulse mode. The selection of laser process parameters was based on the specification of available laser welding machine. Dissimilar laser welding of 304L and st37 carbon steel for full depth of penetration have been performed, with varying average beam power (225-510W) and constant welding speed (5mm/s) and pulse width (5ms).

Findings

Recrystallized coarse grains were observed adjacent to the fusion zone and nucleated grains were seen away from the fusion zone towards carbon steel. Overlapping factor and HAZ width st37 side increases with increase in average beam power whereas top weld bead width increases first, attains maximum value and then subsequently decreases. Bottom weld bead width increases with increase in average beam power. The mechanical properties namely microhardness and tensile strength of the welded joints have been investigated with varying average beam power.

Originality/value

In the recent development of the automobile, power generation and petrochemical industries the application of dissimilar laser welding of austenitic stainless steel (304L) and carbon steel (st37) are gaining importance. Very limited work have been reported in pulsed Nd:YAG dissimilar laser welding of austenitic stainless steel (304L) and carbon steel (st37) for investigating the effect of laser process parameters on weld bead geometry, microstructural characterization and mechanical properties of the welded joint.

Details

World Journal of Engineering, vol. 16 no. 3
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 1 October 2002

Anna Kochan

Reports from the Hanover Fair on new developments in robotic automation, outlines the latest robot hardware and software innovations to be launched on the market, and describes…

Abstract

Reports from the Hanover Fair on new developments in robotic automation, outlines the latest robot hardware and software innovations to be launched on the market, and describes new applications being taken up by industry.

Details

Industrial Robot: An International Journal, vol. 29 no. 5
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 1 June 1998

John D. Williams and Carl R. Deckard

Selective laser sintering (SLS) is a leading process for developing rapid prototype objects by selectively fusing layers of powder according to numerically defined cross‐sectional…

4055

Abstract

Selective laser sintering (SLS) is a leading process for developing rapid prototype objects by selectively fusing layers of powder according to numerically defined cross‐sectional geometry. The process has the potential to become an indispensable industrial tool. However, continuous process improvement is necessary. Improved understanding of the parameter effects on the process response is expected to lead to process advances. In this work the analytical problem describing the energy delivery, heat transfer and sintering process along with other pertinent phenomena is studied. Physical experiments and implementation of a numerical simulation are conducted using Bisphenol‐A polycarbonate. The effects of selected parameters on the SLS process response are examined. The primary parameters of interest are the laser power, laser beam velocity, hatch spacing, laser beam spot size and scan line length. This work shows that the secondary process parameters, delay period and number of effective exposures have a significant influence on the process response.

Details

Rapid Prototyping Journal, vol. 4 no. 2
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 21 December 2023

Mehran Ghasempour-Mouziraji, Daniel Afonso, Saman Hosseinzadeh, Constantinos Goulas, Mojtaba Najafizadeh, Morteza Hosseinzadeh, D.D. Ganji and Ricardo Alves de Sousa

The purpose of this paper is to assess the feasibility of analytical models, specifically the radial basis function method, Akbari–Ganji method and Gaussian method, in conjunction…

Abstract

Purpose

The purpose of this paper is to assess the feasibility of analytical models, specifically the radial basis function method, Akbari–Ganji method and Gaussian method, in conjunction with the finite element method. The aim is to examine the impact of processing parameters on temperature history.

Design/methodology/approach

Through analytical investigation and finite element simulation, this research examines the influence of processing parameters on temperature history. Simufact software with a thermomechanical approach was used for finite element simulation, while radial basis function, Akbari–Ganji and Gaussian methods were used for analytical modeling to solve the heat transfer differential equation.

Findings

The accuracy of both finite element and analytical methods was validated with about 90%. The findings revealed direct relationships between thermal conductivity (from 100 to 200), laser power (from 400 to 800 W), heat source depth (from 0.35 to 0.75) and power absorption coefficient (from 0.4 to 0.8). Increasing the values of these parameters led to higher temperature history. On the other hand, density (from 7,600 to 8,200), emission coefficient (from 0.5 to 0.7) and convective heat transfer (from 35 to 90) exhibited an inverse relationship with temperature history.

Originality/value

The application of analytical modeling, particularly the utilization of the Akbari–Ganji, radial basis functions and Gaussian methods, showcases an innovative approach to studying directed energy deposition. This analytical investigation offers an alternative to relying solely on experimental procedures, potentially saving time and resources in the optimization of DED processes.

Details

Rapid Prototyping Journal, vol. 30 no. 2
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 1 September 1996

Neal K. Vail, Badrinarayan Balasubramanian, Joel W. Barlow and Harris L. Marcus

Reports that measurable amounts of polymer degradation occur during the fabrication of objects from polymer coated ceramic powders by selective laser sintering (SLS). Argues that…

2164

Abstract

Reports that measurable amounts of polymer degradation occur during the fabrication of objects from polymer coated ceramic powders by selective laser sintering (SLS). Argues that because the binder is important in achieving strong green parts that can be handled with minimal breakage during post‐processing operations, it is essential to minimize the extent of binder losses. As the first step towards understanding the mechanisms of binder degradation, this paper presents a thermal model of the physical system, noting that the agreement between theory and experiment are good. The model is used to help determine the most influential parameters affecting binder losses during fabrication from polymer coated powders. Predicts that adjustments to laser beam diameter, laser scanning distance and gaseous environment will strongly affect polymer binder degradation during processing. Further predicts correctly that polymer degradation during SLS processing is not sensitive to the inherent degradation kinetics of the polymer.

Details

Rapid Prototyping Journal, vol. 2 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 1 September 1989

A.P. Hoult

THERE are two main types of lasers in use in industry today. These are CO2 gas lasers, which emit a light beam with a wavelength of 10.6 microns, and solid state lasers, generally…

Abstract

THERE are two main types of lasers in use in industry today. These are CO2 gas lasers, which emit a light beam with a wavelength of 10.6 microns, and solid state lasers, generally Nd:YAG (Neodimium Ytrium Aluminium Garnet) with a wavelength of 1.06 microns. However, the use of lasers in the aerospace industry to date is relatively limited for the following reasons:

Details

Aircraft Engineering and Aerospace Technology, vol. 61 no. 9
Type: Research Article
ISSN: 0002-2667

Article
Publication date: 1 January 1992

S.B. Dunkerton

The increasing complexity of microelectronic devices and the advent of surface mount technology has led to interest in alternatives to mass reflow soldering techniques. One method…

Abstract

The increasing complexity of microelectronic devices and the advent of surface mount technology has led to interest in alternatives to mass reflow soldering techniques. One method with advantages for rapid automation and minimal heat input, is laser soldering. Various laser methods are available for application to reflow soldering, the prime options being continuous wave CO2, continuous wave Nd/YAG and pulsed Nd/YAG. This paper presents the results of work to compare and contrast the three techniques. The paper concentrates on the soldering of leadframes and SMD (gull wing and J‐lead) to plated Al2O3 substrates, but also mentions soldering to FR4 PCBs.

Details

Soldering & Surface Mount Technology, vol. 4 no. 1
Type: Research Article
ISSN: 0954-0911

Article
Publication date: 1 April 1984

M.N. Watson

Many small holes need to be drilled in printed circuit boards to achieve a high packing density of circuit components. Even with NC control, conventional mechanical techniques are…

Abstract

Many small holes need to be drilled in printed circuit boards to achieve a high packing density of circuit components. Even with NC control, conventional mechanical techniques are relatively slow and holes smaller than 035 mm diameter are difficult to achieve in production. Laser drilling has been suggested as a potentially fast technique capable of drilling small holes, so trials have been conducted on thin, flexible kapton board, and on 08 mm and 16 mm thick epoxide woven glass fabric board with 12 and 36 micron thick copper cladding. Using a 600 W CO2 laser, the proposed technique was to pre‐etch holes in the copper which would then act as a mask to the beam, so drilling only where etched holes existed. This technique was feasible on the flexible board, but not on the thicker boards because of damage to the copper. Using a pulsed Nd‐YAG laser to drill through both copper and laminate gave good results, but more work is necessary to eliminate occasional delamination of the copper around the hole. Through‐hole plating of the drilled holes appeared to present no special problems.

Details

Circuit World, vol. 11 no. 1
Type: Research Article
ISSN: 0305-6120

1 – 10 of 122