Peter Šugár, J. Šugárová and M. Kolník
Technology-Based Sheet Metal Classification and Coding System
Group technology (GT) concept uses design similarity measure to identify the most similar design and retrieve a useful process plan. One of the existing formal methods of machine parts classifying for the group technology applications is the coding and classification. The researchers have developed many different GT coding schemes, which very precisely describe the design characteristics of the parts, but many of them do not explicitly describe the process plan. The paper presents a new approach to the sheet metal part coding and classification with plan-based attributes implementation in accordance with the technical standard STN 226001.
Selected Applications of Virtual Reality in Manufacturing
Virtual reality (VR) has become an important and useful tool in science and engineering. VR applications cover a wide range of industrial areas from product design to analysis, from product prototyping to manufacturing. The design and manufacturing of a product can be viewed, evaluated and improved in a virtual environment before its prototype is made, which is an enormous cost saving. Virtual Manufacturing (VM) is the use of computer models and simulations of manufacturing processes to aid in the design and production of manufactured products. VM is the use of manufacturing-based simulations to optimize the design of product and processes for a specific manufacturing goal such as: design for assembly; quality; lean operations; and/or flexibility.
Igor Kačmarčik, Dejan Movrin and Aljoša Ivanišević
One Contribution to the Friction Investigation in Bulk Metal Forming
Friction is resistance to relative motion when one body slides over another. In metal forming operations, both sheet metal and bulk metal forming, friction is undesirable but also unavoidable occurrence. It has negative impact on main process parameters as well as on workpiece quality. In order to obtain accurate results in metal forming experiments or simulations, the precise value of friction has to be known. In this paper several methods for friction evaluations, such as ring test, forward bar extrusion, backward - forward hollow extrusion, twist extrusion are presented and analyzed. A new double backward extrusion model is proposed.
Dragiša Vilotić and Miroslav Plančak
Experimental Tooling for Contact Stress Measurement in Bulk Metal Forming Processes
Knowledge of contact stresses in metal forming operations is essential not only for optimal die design, but also for theoretical and numerical analysis of the metal forming processes. Determination of contact stresses can be performed theoretically and experimentally. This paper presents a tool construction with built-in pin-load cells for experimental determination of contact stresses and friction coefficient at upsetting of prismatic specimen with cylindrical dies. This construction allows measurement of contact stresses in any point of the contact surface of specimen, due to adjustable location of pin-load cells. The adjustments are performed by turning cylindrical dies around its own axis in combination with the change of axial position of the specimen. Experimental determination of contact stresses in upsetting of Ck35 prismatic specimens using cylindrical tools was performed at the Laboratory for technology of plasticity, FTN Novi Sad.
Radu Roşu, Viorel-Aurel Şerban, Alexandra Bucur, Mihaela Popescu and Dragoş Uţu
Caracterisation of Titanium Nitride Layers Deposited by Reactive Plasma Spraying
Forming and cutting tools are subjected to the intense wear solicitations. Usually, they are either subject to superficial heat treatments or are covered with various materials with high mechanical properties. In recent years, thermal spraying is used increasingly in engineering area because of the large range of materials that can be used for the coatings. Titanium nitride is a ceramic material with high hardness which is used to cover the cutting tools increasing their lifetime. The paper presents the results obtained after deposition of titanium nitride layers by reactive plasma spraying (RPS). As deposition material was used titanium powder and as substratum was used titanium alloy (Ti6Al4V). Macroscopic and microscopic (scanning electron microscopy) images of the deposited layers and the X ray diffraction of the coatings are presented. Demonstration program with layers deposited with thickness between 68,5 and 81,4 μm has been achieved and presented.