فهرست مطالب mansour mardalizadeh

Friction stir welding is a solid state process developed by the welding institute TWI in 1991¡ as a technique for welding aluminum alloys. In this research¡ lap joint welding of 5456 aluminum alloy was carried¡ so that the hard working H321 sheet with the thickness of 5 mm was placed on an annealed sheet with the thickness of 2.5 mm and has been investigating the simultaneous effects of parameters such as rotational speed¡ feed rate¡ and tool angle¡ on failure force parameters and the hook disadvantage height in friction stir welding were investigated. After evaluation and analysis of the welded samples; the modelling of multilayer perceptron neural network was carried out using experimental results¡ and for the purpose of the trained model verification¡ several verification models was performed where the results of failure force in training model show 2.017 percent average error with respect to the experimental results. Next¡ the multilayer perceptron neural network was used for investigating the effect of welding parameters as in single or group mode on welding mode variations¡ where rotational speed parameter has the greatest effect and tool angle has the least effect than the other two parameters in lap joint friction stir welding.

Friction stir welding is a solid state process which is developed by Twi institute in 1991. In this paper، lap welding of 5456 aluminum alloy sheets were carried out while hard working H321 sheet with a thickness of 5 mm was on top of a 2. 5 mm thickness annealed sheet and the simultaneous effect of rotation speed of tool، feed rate and tool angle parameters on failure force and the height of hook in friction stir welding were investigated using response surface method. After evaluation and analysis of welding samples، response surface method was used using experimental results and several verification models were performed for error estimation. The results of mechanical properties of model show 3. 88 percent average error with experimental results. In proceeding، the analysis of variance was used for investigation of the welding parameters effect on welding mode variations and it was seen that feed rate has the greatest effect on failure force and rotation speed has the greatest effect on the hook height and tool angle has the lowest effect in comparison with this two parameters.

Friction stir welding is a solid state process which is developed by Twi institute in 1991. In present study، lap joint welding of 5456 aluminum alloy sheets were carried out whiles hard working H321 sheet with a thickness of 5 mm was on top of a 2. 5 mm annealed sheet and the simultaneous effect of rotation speed and tool feed rate parameters on microstructure and micro hardness in friction stir welding were investigated. The results show that the friction stir welding causes crush between metal particles، Microstructure homogenization and fine weld beads. The studies showed that increase of rotation speed and reduction of feed rate (increase of welding pitch) causes increase of heat input، vertical flux، grain size and reduction in hardness. With a closer look It was seen that increase in rotation speed from 250 rpm to 750 rpm in constant feed rate and tool angle، increases the grain size from 4. 65 micrometer to 7. 89 micrometer and feed rate with increasing، the grain size reduced from 7. 11 micrometer in speed of 25 mm/min to 4. 77 micrometer in speed of 75 mm/min.