Product minimization is a global trend in many industries such as medical devices, electronics, communications, aerospace, automotive and military. Microfabrication is focused on producing three-dimensional parts with high precision using various materials and having dimensions from tens of micrometers to several millimeters. The tribological conditions between the tool and the workpiece are of the utmost importance for process feasibility and process quality. This becomes even more prominent as the process shrinks from macro to micron. Today, the use of ultrasonic vibrations in shaping processes is increasing. The main reasons for this expansion are the capabilities and properties created in the process and the material during the ultrasonic vibrations. In this research, in order to overcome the challenges of microforming, finding a suitable lubricant and optimal parameter of ultrasonic oscillations, a set for performing micro-ring compression test (MRCT) with ultrasonic oscillations was designed and manufactured. In this regard, samples of different sizes were subjected to ring compression test with ultrasound. This process was designed in three levels of experiment to study the effect of lubricant, speed and amplitude of fluctuations on friction. It was observed that by adding ultrasonic vibrations to this process, the forces are reduced due to the reduction of the friction force and the yield stress in the material. In this research, with a new technique, the degree of participation of these two quantities in reducing the force of the process was calculated. Also, in all samples, with decreasing sample size, the coefficient of friction in the sample increased and zinc phosphate was identified as a suitable lubricant for microextrusion process. Using MoS 2 grease lubricant with a amplitude of 20 microns in the ring compression test process, the coefficient of friction was reduced by 37.1% compared to the case where the lubricant was not used. In this dissertation, ultrasonic vibrations are also applied to the microextrusion process and its effects on the surface roughness of the sample, corner filling (CF) parameter, microstructure and also the required force of the process are investigated. For this purpose, a system including a microextrusion die and a concentrator of ultrasonic vibrations with a resonant frequency of 20 kHz was designed and fabricated. In two cases with ultrasonic vibrations and without the presence of ultrasonic vibrations, samples of AISI 1015 steel, 1100 aluminum and 99.5% Cu were passed through the die and then the mentioned parameters were examined. It was found that the rate of improvement of surface roughness of micro gear by applying ultrasonic fluctuations varies between 7.6 to 24.1%. The amount of filling in the corner of the die after the presence of ultrasonic vibrations increased compared to normal conditions and this amount increased up to 23.3% in aluminum micro gears. It was shown that ultrasonic vibrations reduced the force required by the process and the maximum reduction of 19% was determined for aluminum micro gear. Keywords: Ring compression test, Microextrusion, Micro gear, Ultrasonic vibration, Friction