EM - Escola de Minas

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Tool life monitoring in end milling of AISI H13 hot work die steel using a low‑cost vibration sensor connected to a wireless system.
(2022) Vianello, Pedro Ivo Alves; Abrão, Alexandre Mendes; Maia, Antônio Augusto Torres; Pereira, Igor Cezar
Machining of complex components with high added value requires the development and implementation of technologies for monitoring the processes outputs and to ensure the performance and reliability of the manufactured part. Cutting tool wear is one of the most relevant variables in machining due to its efect on both the machining cost and quality of the manufactured component. Although tool wear has been extensively investigated for more than a century, the advent of Industry 4.0 has required more accurate and reliable monitoring systems. This work investigates the feasibility of using a low-cost vibration sensor, based on a micro-electromechanical system (MEMS), connected to a wireless data transmission system attached to a rotary tool (milling cutter) for tool wear monitoring when milling annealed AISI H13 hot work die with coated tungsten carbide inserts. A microcontroller with an integrated internet connection connected to a local server through the Wi-Fi network was employed. In order to validate the proposed system, tests were performed comparing its behavior with a conventional piezoelectric sensor in terms of sensitivity to changes in the cutting conditions and tool wear evolution. The results indicated that the proposed system responds satisfactorily to changes in the cutting conditions, with approximately a four-fold increase in the acceleration amplitude when either cutting speed or axial depth of cut were doubled. Although neither the MEMS nor the piezoelectric accelerometer was capable to detect tool wear evolution (considering a tool life criterion VBB=0.3 mm), the RMS value of the signal generated by the vibration sensor based on MEMS is approximately four times higher than that provided by the piezoelectric accelerometer, thus indicating a better representation of the vibration phenomenon resulting from fxing the MEMS on the tool (in contrast to the piezoelectric accelerometer attached to the workpiece).
An approach to torque and temperature thread by thread on tapping.
(2020) Pereira, Igor Cezar; Vianello, Pedro Ivo Alves; Boing, Denis; Guimarães, Gilmar; Silva, Marcio Bacci da
During internal threading, small alterations in cutting parameters, tool geometry, or process characteristics produce considerable effects on torque and temperature behavior. Understanding these effects is critical to the design and development of new taps. In this work, the torque behavior for a tap operation is evaluated as a function of the number of threads, tool manufacturer, and angle of the taper region of the tool. The chip–tool interface temperature was analyzed, considering the influence of cutting speed and number of threads. Experimental tests were carried out using M10x1.5 taps and cutting speeds of 10 m/min and 25 m/min. Taps with two different geometries were considered in this analysis. The results show a difference in the distribution of the torque along the threads of the conical part between the tools. The presence of adhered material increased the torque during the reverse stage. The torque during the reverse stage for a tap with a damaged tooth was approximately 50% of the torque during the cutting stage. The temperature showed an increase with the number of threads stabilizing between the fourth and fifth threads and increasing again in the sixth filled due to adhesion of workpiece material.
Análise da temperatura filete a filete no rosqueamento interno por machos de corte.
(2018) Souza, R. F. A.; Vianello, Pedro Ivo Alves; Silva, Marcio Bacci da; Pereira, Igor Cézar
Among the manufacturing processes, threading stands out, as it can be accomplished by machining or by forming. This process is responsible for the creation of internal and external threads, which has great applicability in production lines. Due to the market’s great competitiveness, methods are sought to increase production by decreasing the time of each unit process. However, tapping is usually performed at low cutting speeds due to limitations related to the manufacturing process. The study of the tapping can bring benefits, such as the reduction of wear mechanisms, resulting in an increase in tool life. In this research, the temperature was measured from fillet to fillet in the conical part of the tool, varying the cutting speed and the number of fillets. The tap used is, M 10 x 1.5 HSS, uncoated in threading process for internal thread production in SAE 1045. To analyze the temperature was used the tool-workpiece thermocouple method on each fillet of the tap. The cutting speeds used were 10 and 25m / min. From the second fillet on the temperature is constant, even with the increase in the number of fillets, as expected.
Análise e comparação do torque filete a filete no rosqueamento interno por machos de corte.
(2018) Vianello, Pedro Ivo Alves; Souza, R. F. A.; Silva, Marina Carla Bezerra da; Pereira, Igor Cezar
The thread process is responsible for internal and external threads creation which are of large application in several areas. Even though its large usage in industry, there are few papers about this process. In this paper, it was carried out torque fillet by fillet measurements over the chamfer portion of the tap and the torque comparation between tools from two distinct manufacturers. It was used M 10 x1,5 HSSE straight flute taps, with and without coating in tapping process on a grey cast iron GG30, in order to analyse the relation between the number of fillets in the tap’s chamfer and its geometry in torque signal behaviour.

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