Effect of the Nano Particle Solution on the Coulomb Friction Behavior of Aluminum Alloy Forming Process Using the Ring Compression Test

Friction is one of the important factors influencing metal forming processes e.g. forging. Besides considering a set of basic principles, efficient lubrication is the best way to control friction and wear. One way to evaluate the effect of lubricants on the friction in forming processes, is ring compression test. By using calibration curves in the forging process, friction coefficient is calculated. In this paper, the effects of nano- particles solution including copper oxide and alumina within paraffin and oil-10 as the base lubricants on the Coulomb friction model has been studied. In order to obtain the optimal design of experiments Taguchi method has been used and considering the number of investigating factors, L8 orthogonal array selected. After carrying out all suggested tests and using calibration curves for Al7xxx, Coulomb friction coefficients for different lubricants have been obtained. Weight percentage of nano-particles and the type of both base lubricant and nano-particles additives, considered as input variables, and the Coulomb friction coefficient selected as objective variable. Through variance analysis the effectiveness of each input variable on the objective evaluated and values of the input parameters to minimize friction coefficient by Taguchi signal-to-noise method were extracted. The results show that the greatest impact belongs to weight percentage of nanoparticles with a share of 62.15 percent on the friction coefficient and increasing the weight percentage of nanoparticles lead to increasing the friction coefficient. Also, the best combination to minimize friction coefficient is 0.8% solution of alumina nanoparticles with oil 10 as base lubricant.