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Osnovna studija topografije površina nastalih rezanjem abrazivnim vodenim mlazom izrađena je uz pomoć spektralne analize tih površina. Početni podatci su prikupljeni primjenom optičkog profilometra MicroProf FRT u obliku 2D karata visina površina. U radu se predstavljeni osnovni pojmovi spektralne analize primijenjeni na topografiju površine. Razmotrena su ograničenja postupka mjerenja. Raspravljena su iskrivljavanja površinske gustoće spektra snage. Procjena površinske gustoće spektra snage je obavljena pomoću metode periodograma u kombinaciji s Welchovom metodom. Uspoređene su površine dobivene rezanjem pomoću abrazivnog vodenog mlaza uz različite vrijednosti tehnoloških parametara rezanja. Pokazano je da se spektralnom analizom navedenih površina nude nove mogućnosti karakterizacije njihove topografije., Abasic study of a surface topography generated by an abrasive waterjet cutting is performed by means of the spectral analysis of these surfaces. The initial data were acquired by using an optical profilometer MicroProf FRTin the form of 2D maps of the surfaces' heights. The basic notions of the spectral analysis applied to the surface topography are presented. Limitations of the measurement procedure are considered. Distortions of the areal power spectral density are discussed. An estimation of the areal power spectral density is carried out using a periodogram method combined with the Welch´s method. A comparison of surfaces prepared by the abrasive waterjet cutting with different values of the cutting technological parameters is performed. It has been demonstrated that the areal spectral analysis of the aforementioned surfaces offers new possibilities of their topography characterization.

The paper deals with experimental research and evaluation of side milling by evaluation of technology factors, which influence the surface profile parameter peak to valley of high-grade steel E295 by means of design of experiments. Four selected technological factors (diameter of milling cutter, spindle speed, feed per tooth and depth of cut) which enter into technological process of side milling of slots have been evaluated by means of full factories analysis. The surface quality has been evaluated by static quality characteristic the peak to valley Rz parameter. The multiple linear regression equation obtained after analysis of variance gives the level quality Rz as a function of the significant factors. Different factors main effect and their interaction significance have been found, which generated surface profile under defined conditions by side milling., U radu je prikazano eksperimentalno istraživanje i procjena bočnog glodanja pomoću procjene tehnoloških čimbenika koji utječu na parametar profila površine visokokvalitetnog čelika E295 pomoću pokusa. Četiri odabrana tehnološka čimbenika (promjer glodala, brzina osovine, sadržaj po zubu, dubina rezanja) koji spadaju u tehnološki proces bočnog glodanja utora ispitana su pomoću potpune analize čimbenika. Kvaliteta površine je ispitana pomoću Rz parametra. Višestruka jednadžba linearne regresije dobivena nakon analize varijance daje razinu kvalitete Rz kao funkciju važnih čimbenika. Uočen je glavni utjecaj raznih čimbenika i važnost njihova međudjelovanja, koji su dali profil površine u zadanim uvjetima pomoću bočnog glodanja.

The paper deals with the study of using continuous water jet and ultrasonic pulsating water jet for bone cement disintegration. Bone-cement Pallacos R+G (manually mixed) was disintegrated ex-vivo. Mechanical properties of the bone cement were determined by nano-indentation. Factors employed in evaluation were pressure (40, 80, 120) MPa and traverse speed for continuous water jet, pressure (8, 10, 12, 14, 16, 20) MPa and orifice type (flat, circular) for ultrasonic pulsating water jet. Depth penetration h (mm) was measured by non- contact optical profilometer MicroProf FRT. Results represent the first step towards feasibility of using effective water jet technique during reimplantation of cemented endoprosthesis, for bone cement removal from femoral canal without heat and mechanical damage of surrounding tissue.

Strojevi, oprema i njihovi dijelovi koji se koriste u poljoprivredi, naime u području obrade tla, izloženi su intenzivnom abrazijskom trošenju. Važni proizvođači poljoprivednih strojeva upotrebljavaju sinterirane karbide, naime tungstenov karbid, u alatima za obradu tla. Alternativa ovom rješenju je uvođenje keramičkih materijala koji su se dokazali pozitivnim otporom na trošenje. Ovaj se rad bavi mogućnošću primjene keramičkih materijala i ljepila u alatima korištenim za obradu tla. Laboratorijska ispitivanja pokazala su da se odgovarajućim izborom ljepila povećala krutost sustava što znači da je porasla apsorpcija energije tijekom udara na keramičku površinu. Ispitivan je keramički materijal Al2O3. Cilj istraživanja je procjena jačine smičnog udara adhezivnih spojeva i mogućnosti uporabe keramičkih materijala kao materijala otpornih na trošenje u području obrade tla. Primjena tog rješenja zahtijeva bavljenje tehnologijom adhezivnog spajanja pri dobivanju postojanih i čvrstih spojeva, a to znači međudjelovanje keramika/čelik., Machines, equipment and their partial segments used in agriculture, namely in the sphere of soil cultivating, are exposed to an intensive abrasive wear. Important producers of agricultural machines use sintered carbides, namely the tungsten carbide in the soil cultivating tools. The alternative to this solution is introducing the ceramic materials which have proved their positive wear resistance. This paper deals with the application possibility of the ceramic materials and adhesives in the tools used for cultivating the soil. Laboratory tests showed that a suitable choice of adhesive increased the system rigidity which means the energy absorption was increased during the impact on the ceramic surface. The ceramic Al2O3 was tested. The aim of the research is the evaluation of shear impact strength of adhesive bonds and the possibilities of using the ceramic materials as the wear resistant materials in the sphere of soil cultivation. Application of this solution demands coping with the adhesive bonding technology in obtaining firm and strong bonds which means the ceramics/steel interaction.

Additive Manufacturing (AM) is close to become a production technique changing the way of part fabrication in future. Enhanced complexity and personalized features are aimed. The expectations in AM for the future are enormous and betimes it is considered as kind of the next industrial revolution. Laser Sintering (LS) of polymer powders is one component of the AM production techniques. However materials successfully applicable to Laser Sintering (LS) are very limited today. The presentation picks up this topic and gives a short introduction on the material available today. Important factors of polymer powders, their significance for effective LS processing and analytical approaches to access those values are presented in the main part. Concurrently the exceptional position of polyamide 12 powders is this connection is outlined., Procedia Engineering, 149, International Conference on Manufacturing Engineering and Materials, ICMEM 2016

The paper presents application of weld thermal cycle simulator for investigations and data predictions after welding process and post weld heat treatment of base material. Along with basic description of thermal cycle simulator Smitweld TCS 1406 and influence of weld thermal cycle on mechanical properties and micro structure of base metal, the authors provided some practical data obtained on specimens after thermal simulation. This approach is often used for acceleration of weldability investigations combined with additional investigations (e.g. hardness and toughness determination, micro structure investigation, etc.) and other investigations (e.g. post weld heat treatment, casting, hot metal forming, etc.). With weld thermal cycle simulator it is possible to reduce duration and costs of production (e.g. investigations at PQR/WPAR, PWHT).