Search results

Aims to review polymeric materials used as adhesives and the related bonding procedures applicable in the medical industry.

The main types of polymeric materials used as adhesives are described. Details and the main points of the adhesive bonding processes are also described with comments on their adaptability to automated assembly. Finally, typical examples of the use of adhesives in medical device applications are provided.

Review paper with examples of applications of adhesives in assembly of medical materials and devices.

The appropriate selection of adhesive types and bonding parameters are critical for successful application of this technology in joining medical materials. Most currently available medical grade adhesives are only suitable for short‐term (<30 days) implantable application. The users must ensure that the properties of the selected adhesives, particularly the relevant biocompatibility and toxicity data are available and fully comply with any specific medical device application and regulation.

Although this is a general review paper, it contains information about new materials and processing techniques applied in successful application of adhesive bonding technology in medical devices. The information provided is expected to be of significant benefit to material scientists and design engineers evaluating and identifying suitable joining techniques for the assembly of medical devices.

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.

Most of the machine parts can be produced using several manufacturing methods, such as forging, machining, casting or welding. The type of manufacturing method may be selected with respect to production costs of the alternatives for individual parts. In the presented study, an experimental friction welding set‐up was designed and constructed in order to investigate the effects of some welding parameters on the welding quality. The set‐up was constructed as continuous‐drive. Several groups of specimen were machined from the same material. Some pilot welding experiments under different process parameters were carried out in order to obtain optimum parameters according to statistical approach. The strengths of the joints were determined by tension tests, and the results were compared with those of specimen's material. Addition to the tensile test data, hardness variations and microstructures in the welding‐ zone were obtained and examined.

Aims to determine if friction welding is suitable for welding austenitic stainless steel (AISI 304)

Uses an experimental continuous drive friction welding set‐up. Determined the strength, hardness and microstructure of the joined parts.

Finds that the joint strengths are 96 per cent of those of the base metals with no significant hardening.

Friction welding is an appropriate joining method for austenitic stainless steel (AISI 304).

Aids in understanding appropriate uses of friction welding for joining stainless steel.

In the presented study, AISI 1040 medium carbon steel and AISI 304 austenitic stainless steel parts were joined by friction welding. The welding process was carried out under optimized conditions using statistical approach. Tension tests were applied to welded parts to obtain the strength of the joints. Fatigue properties were additionally obtained experimentally under fluctuated tensile loads. Finally, notch impact tests were applied to the joints. Microstructures using microphotographs were examined in the heat affected zone of welded parts. Hardness variations in welding zone were also obtained. Experimental results were compared with those of previous studies.

This study aims to review the effect of copper percentage in Sn-based solder alloys (Sn-xCu, x = 0–5 Wt.%) on intermetallic compound (IMC) formation and growth after laser soldering.

This study reviews the interfacial reactions at the solder joint interface, solder joint morphology and the theory on characterizing the formation and growth of IMCs. In addition, the effects of alloying and strengthening mechanism, including wettability, melting and mechanical properties are discussed.

This paper presents a comprehensive overview of the composition of tin-copper (Sn-Cu) solders with a potential to enhance their microstructure, mechanical characteristics and wettability by varying the Cu percentage. The study found that the best Cu content in the Sn-xCu solder alloy was 0.6–0.7 Wt.%; this composition provided high shear strength, vibration fracture life value and ideal IMC thickness. A method of solder alloy preparation was also found through powder metallurgy and laser soldering to improve the solder joint reliability.

This study focuses on interfacial reactions at the solder joint interface, solder joint morphology, modelling simulation of joint strength and the theory on characterising the formation and growth of IMC.

The paper comprehensively summarises the useful findings of the Sn-Cu series. This information will be important for future trends in laser soldering on solder joint formation.

The present study seeks to examine the possibilities of combined usage of friction welding and plastic forming in recycling of bar‐shaped waste materials.

If the waste materials can be reproduced using various manufacturing methods without melting, their economic values could be increased economically. For this reason, using a combination of friction welding and plastic forming was chosen as an alternative recycling method. Upsetting was chosen as the plastic forming method due to its ease of application.

In the present study, dimensional changes, hardness variations in heat affected zone (HAZ), variations of torsion and tensile strengths with upsetting ratio of specimens were examined. Hardness values of test material are raised to higher levels within the HAZ by the local hardening. The maximum shear stress in torsion and the tensile strengths of specimens are closely harmonious with hardness values of test material.

Although it was observed in general that the increasing upsetting ratio increased the torsion and tensile strengths, experimental study must be improved and extended in order to obtain more precise results.

It can be concluded that combined usage of just welded and additional cold deformation can be considered as an alternative recycling method owing to obtained positive results.

This paper helps individuals reutilize waste materials because of the small lengths of the bars. Furthermore, it can be observed that the combination of friction welding and plastic forming produces savings in the material and the cost in this study.

Reviews the development of the corporate social responsibility (CSR) concept and its four components: economic, legal, ethical and altruistic duties. Discusses different perspectives on the proper role of business in society, from profit making to community service provider. Suggests that much of the confusion and controversy over CSR stem from a failure to distinguish among ethical, altruistic and strategic forms of CSR. On the basis of a thorough examination of the arguments for and against altruistic CSR, concurs with Milton Friedman that altruistic CSR is not a legitimate role of business. Proposes that ethical CSR, grounded in the concept of ethical duties and responsibilities, is mandatory. Concludes that strategic CSR is good for business and society. Advises that marketing take a lead role in strategic CSR activities. Notes difficulties in CSR practice and offers suggestions for marketers in planning for strategic CSR and for academic researchers in further clarifying the boundaries of strategic CSR.

Date: 26 October 1994 Venue: The Regency Hotel, Shirley, Solihull, West Midlands This conference will highlight technological advances being made as we approach the 21st century. Papers cover a wide range of scientific and technical developments and latest advances in production techniques, particularly those which may involve environmental considerations. The programme will appeal to end‐users, planners, designers and production technologists, as well as development engineers and scientists.

The programme will cover various aspects of high technology joining processes ranging from soldering and brazing to diffusion and adhesive bonding. The papers presented will cover the latest developments in production techniques, methods of enhancing quality, joint inspection, new or improved materials, design/properties of joints and long‐term reliability.