Marek Pagáč

Mechanisms of cutting blade wear and their influence on cutting ability of the tool during machining of special alloys

With increased requirements for quality and shelf life of machined parts there is also a higher share of the use of material with specific properties that are identified by the term “superalloys”. These materials differ from common steels by mechanical and physical properties that cause their worse machinability. During machining of “superalloys” worse machinability has negative influence primarily on the amount of cutting edge wear, which shortens durability of the cutting tool. The goal of experimental activity shown in this contribution is to determine individual mechanisms of the cutting edge wear and their effects on the cutting ability during high speed machining of nickel superalloy. A specific exchangeable cutting insert made from cubic boric nitride was used for machining of the 625 material according to ASM 5666F. The criteria to evaluate cutting ability and durability of the cutting tool became selected parameters of surface integrity and quality of the machined surface.

Impact of cutting tool geometry on the dynamic load of system in the machining process of nickel Alloy 625

The article is focussed on comparing and determining the impact of the cutting geometry of the cutting tool due to dynamic load on system and microgeometry machined surface. For longitudinal turning nickel alloy Alloy 625 (W. Nr. 2.4856) rounded indexable cutting insert was used (RCMT 10T3M0 – F2) and its equivalent squared indexable cutting insert (SNMG 120412 – MR3) coated with fine-grained PVD (Ti, Al) N + TiN. Experimental testing of nickel Alloy 625 was under predetermined cutting conditions. In the selected depth of the removed material of 0.5 mm and 1.5 mm was measured in the course of machining the size of the individual components of cutting forces.

The Use of Technology Local Heating by Laser for Turning of Difficult to Machine Materials

The article deals with the use of the local laser heating during turning of hard machined materials. The application of heating using laser technology is applied especially to reduce the wear of cutting tools and increasing their durability and decreasing costs associated with machining process. The aim of the experiment was to compare the costs associated with production of a valve seat made of CrNi 58/41. Current machine equipment was replaced by RNC 400 Laserturn hybrid lathe. The choice of the proposed solution was verified on the basis of technical and economic evaluation.

Comparison of Hardness of Surface 316L Stainless Steel Made by Additive Technology and Cold Rolling

The paper deals with the comparison of surface hardness and porosity of stainless steel 316L (1.4404) produced by additive technology (SLM) and cold rolled steel. The subject of the paper is a comparison of two sets of samples where the first set of samples was made on a Renishaw AM400 with a laser output of 200 W and 400 W. In each set of samples, were the samples without heat-treated and heat-treated by annealing. Measurement of porosity and surface hardness were performed on all samples. The surface hardness of the material was evaluated by a static test according to Brinell CSN EN 10003-1. The porosity measurement was performed by the optical method. The measured values were compared with the reference material, which was cold-rolled steel, in which both the porosity and the hardness of the surface were measured.

THE EFFECTIVENESS OF STRATEGIES PRINTING PRINTER EASY 3D MAKER

The article tackles the possibilities and effectiveness of different printing strategies on Easy 3D MAKER printer. This printer uses Fused Deposition Modeling (FDM) method. The operating software of the 3D printer offers various settings, which influence the quality and efficiency of printing. In the article there is described the printing of a sample with all fillament print strategies available in the 3D maker software. The fillament print strategy of the printed model fundamentally influences the consumption of printing material and time at printing the component. The consumption of printing material was assessed indirectly by weight of particular printed samples. For each printing strategy there were 5 samples printed out. The Octagramspiral strategy resulted as the best in material consumption aspect. The most effective strategy in printing time perspective is the Concentric strategy.

Detection of grinding burn through the high and low frequency Barkhausen noise

Rad razmatra pojavu ostecenja povrsine nakon brusenja putem nedestruktivnog mikro magnetskog nacina rada temeljenog na Barkhausenovom sumu. Uspoređuju se metode visoke i niske frekvencije i njihova osjetljivost u otkrivanju povrsinske opekline i debljine zone pod utjecajem topline. Rezultati istraživanja pokazuju da se metodom niske frekvencije može jasnije otkriti povrsinska opeklina nego metodom visoke frekvencije zbog relativno velike debljine zona pod utjecajem topline nastalih nekon brusenja. U radu se također raspravlja o dodatnim aspektima mikro magnetskog ispitivanja kao multi parametrijske metode u kojoj su parametri kao sto je vrsni položaj petlje Barkhausenovog suma u korelaciji s toplinskim opterecenjem obrađivane povrsine. U radu se također daju odgovarajuce promjene u strukturi i s tim povezano naprezanje ispod povrsine.

Effect of chip breakers on the cutting force during the machining of steel C45

The paper deals with the dependence of cutting force on the breaker of an indexable cutting insert (ICI). The experiment monitored individual cutting force components for different insert breakers, cutting speeds and feed rates during machining. The cutting depth remained constant. The tool holder, material and coating of the indexable cutting insert was also identical.

Laser Cutting of Materials of Various Thicknesses

Thise paper deals with the application of laser technology and optimizing the parameters for cutting nickel alloy. The theoretical part of the paper describes various types of lasers, their principles and usage. The experimental part focuses on optimizing the section parameteres of Haynes 718 alloy using a CO2 gas laser. This alloy is employed in the production of components for the aircraft industry. The experiment was performed on the Wibro Delta laser system designed for sizable parts. The actual section is measured with respect to its quality and any accompanying side effects that occur during the process. In this case, laser output and cutting speed were the parameters with most influence on the final cut. The summary explains the results achieved in a metallographic laboratory.