Modern Machinery (MM) Science Journal, November 2010

ANALYSIS AND SIMULATION OF NONLINEAR SELF-EXCITED VIBRATIONS IN MACHINE TOOLS

J. Zeleny, T. Repak, P. Fojtu
Keywords: vibrations | Machine tools | machining process | Machining

Commonly applied theories of self-excited vibrations in machine tools are prevailingly based on frequency domain analysis of linear models, and in most cases only focus on evaluation of stability limits of strictly linear systems. In this way the behaviour of more stable or more unstable systems cannot be studied and analyzed. Neither is it possible to study certain important nonlinear effects beca (…)

USING SIMULATION APPROACH FOR DESIGNING OF ACID PICKLING LINES

S. Simeonov
Keywords: Production Rate | Transport System | Acid Pickling Lines | Discrete Simulation

Presented paper deals with problems of discrete simulation within acid pickling lines. These types of lines are complicated mechanical systems required special algorithm for controlling. The paper discussed using of simulation approach both for projecting and controlling of acid pickling lines. Several experiments with the simulation model were performed to verify the production system design. In t (…)

DESIGN AND MATERIAL OF LARGE COMPLICATED CASTINGS OF STAMPING DIES FOR AUTOMOTIVE INDUSTRY

A. Herman
Keywords: casting design | grey iron | steel | stamping die casting | ductile iron

This research report deals with analysis of large shape-difficulty casting of stamping die for automotive industry – made from materials steel, grey iron and ductile iron. The main goal of this research is to choose a material for any type of stamping die. Second goal is to find problematic areas in the casting design and to change the stamping die design and to recommend optimal technology for cas (…)

QUALITATIVE ANALYSIS OF COMPOSITE ZN-PTFE COATINGS

M. Pazderova, M. Bradac, M. Vales
Keywords: Raman spectroscopy | IR spectroscopy | PTFE | Zinc coating | Composite coating

The aim of this work is to obtain completely new technology of surface treatment. Studies and research in the area of deposition showed that lubricant composite coatings based on zinc with PTFE (polytetrafluoroethylene) particles offer unexpected possibilities of electrodeposition and innovative approach to surface protection. Integral part of this research is a characterisation of applied coatings (…)