The objects of this work were nine different copper-based friction linings produced from powder by pressing and sintering. Six copper-based friction linings contained 3 wt.% zinc (Zn) and variable content of tin (Sn), i.e. 1, 2, 4, 6, 8 and 10 wt. %. Three copper-based friction linings were with fixed contents of Zn (3 wt.%) and Sn (10 wt.%), and with different amount of SiC particles, i.e. 2, 4 and 6 wt.%. Tribological studies on these friction linings included determination of the static and kinetic coefficient of friction under different normal loads and unlubricated sliding conditions, as well as, determination of the abrasive wear resistance under different normal loads and unlubricated sliding/rolling conditions. The analysed results present the influence of Sn content and addition of SiC particles to the copper-based friction lining on its friction and wear properties.

A B S T R A C T A technology to improve the tribological and mechanical surface properties of iron alloys is developed based on

Statistical process control (SPC) can help manufacturers improve the quality of their products. This paper describes a relatively simple and effective method and algorithm to adjust the accuracy of parts produced on CNC machine tools using the methods of statistical process control. Examined the possibilities of the proposed method by computer simulation of the process. By using the proposed algorithm scattering of size is placed in the middle of the tolerance zone. Various variants carrying out the method are proposed adequate on the machining time during processing details in the sample. This can optimize the total time for processing of the batch.

Traditionally fixture design processes are costly and time-consuming when carried out manually. To try to reduce the negative features, we are creating a computer-aided fixture design system, integrated in the SolidWorks' environment. This system uses rule-based reasoning in the form of If-Then-Else rules, incorporated in its VB.NET code. This paper presents our progress in the form of an interactive add-in program for locating parts. This program generates modular fixtures for locating prismatic or cylindrical parts, using rules and mathematical equations. Its usage can shorten the time needed for determining the type and position of every module of the fixture, their assembling, and inspection.UDC Classification: 004.42; DOI: http://dx

This research examines the statistical method for quality control. The accuracy of parts is controlled statistical evaluation - an average and a dispersion of the indicator for accuracy. This paper reports a method for quality control of parts of average indicators and algorithm for quality control of the average and dispersion of samples of small size. It proposes a criterion of applicability of statistical adjustment of accuracy by sampling for control of the average data of the quality indicator. It proves the influence of the dispersion of the quality indicator for impairing the quality of the process.