Search Results

1 - 2 of 2 items

  • Author: János Líska x
Clear All Modify Search

Abstract

Research in 60s and 70s started to deal with the shape of the chip characterization. It was possible then to do a limited study by means of measuring tool park. During such a study, different models for chip formation became familiar, such as the Time or Merchant model. The aim of article is to gain insight into some accompanying phenomena, occurring while cutting of different materials and with various tools. During an experimental design, the possible effects of different variables on each other and individually were considered. Two work-pieces (C45, POM) with two inserts (with two different edge design) were tested while changing of cutting speed and feed. During measurements cutting forces at 5000 Hz signal reception were tested or the evolution of cutting temperature at different experimental settings was evaluated. The chip characteristics are measured by a high speed camera. The camera is connected with PC for recording and controlling the experimental procedure in real-time. The frequency of High Speed Camera was similar than the frequency of the cutting force measuring system. This similarity is provided with the system set-up synchronization.

Abstract

The paper is focused on the experiment where the effects of the cutting environment and feed of drilling on the bores roughness and cylindricity were evaluated. Dry drilling of aluminium alloys (without using cutting fluids) is an environmentally friendly machining process but also an extremely difficult task, which is due to the tendency of aluminium to adhere to the drills made of conventional materials such as high-speed steel; and therefore three cutting environments (namely two different emulsions and compressed air) were used in the experiment. The article demonstrates multicriterial optimization of input factors (cutting environment, feed) for two defined target functions: roughness and cylindricity). The measured values were subjected to mathematico–statistical Analysis of Variance (ANOVA). ANOVA was used for examining the effects of machining parameters and their contribution to the surface roughness and bores cylindricity. The optimal cutting parameters were evaluated for “Smaller-the-Better” quality characteristics of both output responses, as can be seen in our article published previously. Based on the ANOVA, we determined that cutting environment exhibited higher percentage of contribution on bores quality than feed of machining. The results show 77.37 % impact of cutting environment and 8.13 % impact of feed on quality of machined bores.