Nowadays the usage of glass fibre-reinforced plastics (GFRP) is increasing. The cutting of these materials entails several problems, e.g. the strong abrasive wear effect of the glass fibres or delamination effects. In this paper, we examine the results of drilling experiments on a 10 mm thick GFRP which included 26 layers. The cutting parameters were changed over a wide range. During the experiments, we measured the average surface roughness parameter (Ra). After the tests, we examined the effect of the cutting parameters on the measured roughness values. We created two types of predictive model to estimate the roughness parameter and compared their applicability.
The use of fiber-reinforced plastics has increased significantly in the past decades. Consequently, the demand for finishing and machining of such materials has also escalated. During machining, the fiber-reinforced materials exhibit machining problems dissimilar to the problems of metals. These are fiber pull-out, fiber breakage in the cutting zone, matrix smearing and delamination. The purpose of this experiment is to investigate the characteristics of the resultant force (Fe) dur-ing the milling of carbon fiber reinforced plastic as a function of input machining parameters. For the force measurements, CFR with perpendicular (0°-90°) fiber orientation was machined. The experimental design involved the central composite design method. To analyze and evaluate the measurements, we applied the response surface methodology.
Cutting with TiAlN or CrAlN tip PVD-coated tungsten carbide-based inserts manufactured by powder metallurgy, we found no significant difference in the wear behavior of inserts regardless of whether the insert was used in wet or dry conditions. We determined the adhesion properties of the coating layers with a scratch test and by Daimler–Benz test. On the tungsten-based carbide cutting tool, the thinner TiAlN coating showed slightly better adhesion than the thicker CrAlN coating.
There is a growing gap between higher education systems and the needs and demands of the labor market. Many of today’s students will work at jobs that just have emerged or do not even exist yet. The “newcomers” will need both digital and social-emotional skills in the coming years. These new competencies will make the new generation of employees’ company goals. This article presents the results of the recent research about modern-day competencies to evaluate what exactly relevant companies’ expectations are, how students see their knowledge and value in future workplaces, and how academia is coping with this new demand. For this analysis, I have conducted deep interviews with applicable entities, namely companies from the car industry and from the field of security industries (cyber security, integrated camera surveillance, financial security) to see how Industry 4.0 shapes the competencies they expect from our students entering to the job market. Engineering students - by questionnaire -were also interviewed at the Óbuda University, to examine their views about the skills gained at the university and how these competencies helping them to apply for the right position in the job market. Although the competence list showed similarities in the expected skill sets, the order of them differs. While most companies are aiming to hire team players with creative problem solving and those are capable and willing to accept changes, the students’ observations showed that technical skills, expertise, and problem solving are the most important competencies for future employment. Based on all participants’ answers and additional research, we aim to involve international companies to take part in our higher education system more thoroughly either by widening the practical in-site education or by inviting them to our university for lecturing future engineers. Furthermore, new courses are introduced at our university, such as information security, humanitarian response management, rehabilitation environmental planning engineering or ergonomics and human factors specialization.
Super duplex stainless steels are used in increasingly more areas. The machinability of duplex stainless steels is generally poor. We performed dry turning tests on G X2CrNiMoCuN 26-6-3-3 casted superduplex steel, using two different PVD coated cutting inserts. One of them was coated with TiAlN and other with TiAlSiN. Strong burr and built-up edge formation were observed during our machining experiments; these damaged the edges of the tools. The shortened tests did not show significant difference betwen the effect of the coatings.