H. Erol Akata

Joining with friction welding of plastically deformed steel

Abstract Friction welding finds increasingly widespread industrial application as manufacturing method for joining parts. In the present study, an experimental set up was designed and realised in order to achieve the friction welding of plastically deformed steel bars. The parts having same and different diameters deformed plastically, but same material was welded with different process parameters. The strengths of the joints were determined by tension tests. Hardness variations and microstructures in the welding zone were obtained and the effects of welding parameters on the welding zone were investigated.

An experimental study on friction welding of medium carbon and austenitic stainless steel components

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.

An investigation on the effect of dimensional differences in friction welding of AISI 1040 specimens

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 specimens material. Addition to the tensile test data, hardness variations and microstructures in the welding‐ zone were obtained and examined.

An investigation into reutilizing of waste materials using friction welding and upset manufacturing methods

Purpose – The present study seeks to examine the possibilities of combined usage of friction welding and plastic forming in recycling of bar‐shaped waste materials.Design/methodology/approach – 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.Findings – 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.Research limitations/implications – Alt...

An investigation on the variation of surface areas in upsetting of cylindrical specimen

Purpose – The purpose of presented study is to investigate the development of the barreling obtaining the variation of the surface area during upsetting of cylindrical specimens for various metals and alloys.Design/methodology/approach – Variations of the surface areas were first obtained analytically using mathematical equations for uniform and non‐uniform upsetting. Barreling contours were accepted as circular segments in the development of the equations. In the experimental part of the study, barreling radii and other related dimensions of upset specimens were measured and inserted into the developed equations in order to obtain the variations of total specimen surface areas.Findings – As it is expected, barreling effects the variation of total surface areas of the specimen. It can be concluded that the total surface area first decreases at low upset ratios for all the test materials and then begins to increase as the upset ratios increases. Consequently, total surface areas for non‐uniform upsetting a...