Abstract: Friction welding processes are used in diverse areas such as the naval, automotive, and aerospace sectors. These processes offer great flexibility and energy efficiency in the generation of joints. Friction crush welding is a solid-state joining process in which a rotating tool operates along a joint line between two parts generating frictional heat and mechanical agitation to form a joint. In this work, the design and construction of a friction crush welding machine is presented, the stages included: a) the welding disc design, b) calculus of sheets, c) selection of the motor-screw advancement and d) calculus of the support structure. In the evaluation of the equipment, weld joints of Zn-22% Al-2% Cu (zinalco) and Al A380 alloy were developed presenting weld beads with a continuous material flow.

Resumen: Los procesos de soldadura por fricción son utilizados en áreas diversas tales como el sector naval, automotriz y aeroespacial. Estos procesos ofrecen una gran flexibilidad y eficiencia energética en la generación de uniones. La soldadura de fricción por aglomeración es un proceso de unión en estado sólido, en el que una herramienta giratoria opera a lo largo de una línea de unión entre dos piezas generando calor por fricción y agitación mecánica para formar la unión de soldadura. En este trabajo, se presenta el diseño y construcción de una máquina de soldadura de fricción por aglomeración, considerando las etapas: a) diseño de disco de soldadura, b) cálculo en la preparación de láminas, c) selección del motor - tornillo de avance y d) cálculo de la estructura de soporte. En la evaluación del equipo se desarrollaron uniones de soldadura en aleaciones ligeras de Zn-22% Al-2% Cu (zinalco) y Al A380 generando cordones de soldadura con un flujo continuo de material.

The combined processes; rapid solidification, addition of Cu3P compound and heat treatments to improve the mechanical properties of the hypereutectic Al-13Si, Al-20Si and Al-20Si-1.5Fe-0.7Mn alloys (in wt. %) was studied. Optical microscopy and scanning electron microscopy were used to characterize the microstructures. The mechanical properties were evaluated by tensile tests. It was found that the cooling rate (20-50°C/s) used to solidify the alloys plus the addition of Cu3P compound favored the formation of fine primary Si and the transformation of the Al/Si eutectic from acicular to semi-transformed morphology. The spheroidization of the Al/Si eutectic after heat treatment caused an increase in the elongation (%) compared with the as-cast alloys. Al-13Si alloy showed the highest UTS and elongation (%) values, reaching values up to 215 MPa and 9.6%, respectively. On the other hand, the Al-20Si-1.5Fe-0.7Mn alloy showed the lowest UTS (180MPa) and elongation (3.4%) values. The formation of the Fe-intermetallic compounds caused a negative effect on the mechanical properties of the Al-20Si-1.5Fe-0.7Mn alloy.

The present study focuses on the effect of various degrees of plastic deformation generated by cold radial forging on the mechanical properties and the fracture morphology of 32 CDV 13 steel. The cold forging percentage was evaluated for 17.45, 33.30, 42.0 and 46.47 %. The microstructural analysis of the steel shows tempered martensite. The tensile strength, yield strength and hardness were found to increase with the increase of cold forging percentage due to the energy stored in the material during cold forging. For higher cold forging percentage, the toughness of the material was decreased according to the reduction of absorbed energy obtained during deformation. Fractography of the Charpy impact specimens shows a surface roughness and dimple pattern for the steel as was acquired and for 17.45 and 33.3 % of cold forging; while for 42 and 46.47 % of cold forging a cleavage fracture pattern was observed.