Search

Friction stir processing (FSP) is a novel method of metal surface modification during the process by the addition of strengthening particles. FSP produced refined microstructures with the development of added ceramic particles on surface metal. In this FSP, mechanical characteristics were enhanced by FSP parameters, tool spinning speed, traverse speed and the axial force of high carbon high chromium die steel (non-consumable tool). In this research, FSP technique was employed on the surface of the base metal AA6082 aluminium alloy to modify composites of metal surface utilizing Cr3C2 particles. Mechanical properties like tensile strength, processed surface hardness and microstructure were studied. This research mainly focused on the parametric optimization of FSP on AA6082 with multiple responses (tensile strength and processed surface hardness) based on Taguchi L9 orthogonal array and grey relational analysis (GRA). The significant FSP parameters were obtained by grey relational grade (GRG) with an analysis of variance tool. Axial force and traverse speed were the most significant FSP parameters, which the most influence of performance characteristic of friction stir processed specimens. The predicted values were validated by confirmation test at setting of optimum level exhibits better conformity with investigational values. Field Emission Scanning Electron Microscope (FESEM) was carried out to determine the presence of strengthening particles in the processed Aluminium alloy.

Friction stir-welding of AA7075 has become widely practiced in the fabrication of light-weight structures requiring high strength-to-weight ratios and superior corrosion resistance. The friction stir-welding (FSW) process and tool parameters play a key role in determining the joint's characteristics. In this paper, the corrosion resistance of a friction stir-welded alloy was studied via polarization and electrochemical impedance spectroscopy in 3.5% NaCl. The microstructure of different positions along the thickness of the aluminium alloy plate has been investigated with regard to varying parameters, including rotary speed and transverse speed. The heat-affected zones of the weld exhibited the highest susceptibility to inter-granular corrosion. The results also show that sound joints in AA7075 can be achieved using friction stirwelding. Corrosion resistance decreases with the increase of traverse speed from 0.37 to 0.76 mm/s at a rotary speed of 800 rpm. Corrosion resistance at a rotary speed of 1000 rpm is lower than that at 1200 rpm; an increase in the corrosion resistance may also be reached via the breaking down and dissolution of the inter-metallic particles. Prispevek pri tem raziskovalnem delu je bila preučitev vpliva procesnih parametrov na korozijsko obstojnost aluminijeve zlitine AA7075, varjene z gnetenjem. Varjenje z gnetenjem (FSW) je v primerjavi z navadnim laserskim varjenjem, ki spada med talilne postopke, okolju prijaznejša in energijsko varčnejša tehnologija. Varjenje z gnetenjem je bilo uporabljeno tudi v eksperimentih in analizah izboljševanja korozijske obstojnosti. Aluminijeva zlitina AA7075 (Al-Zn-Mg-Cu) je ena od najmočnejših aluminijevih zlitin, ki se danes uporablja v industriji. Zaradi dobrega razmerja med trdnostjo in težo ter njenih značilnosti naravnega staranja je lahko primerna za številne dele letalskih konstrukcij. Pri postopku varjenja z gnetenjem se plastično stanje kovine doseže s posebej zasnovanim valjastim orodjem z ramenskim delom in varilnim čepom malega premera, ki se vrti med dvema sočelno staknjenima površinama in tako ustvari močan zvarni spoj.