Side milling capability of rock cutting tools
Currently, the deviating hole drilling occupies a leading role in Russia. Directional drilling is used when the wells for oil and gas in Western Siberia, in the north of the European part, in the North Caucasus, in Tatarstan, Bashkortostan, Samara region and other areas are drilled, as our regions have a vast number of factors interfering with conventional drilling.
Influence of Technological Factors on Structure and Properties of Alumina-Zirconia Ceramics
The article is devoted to the investigation of alumina-zirconia ceramics properties depending on its production technology. Analysis of the technological factors that allow acquiring fine-grained structure as well as high physical and mechanical properties of alumina-zirconia ceramics is presented in the paper. It is shown that when using magnetic pulse compaction due to the pulse impact and adiabaticity of the process the most compact structure is formed. It is possible to obtain pressings with the density of up to 68% of the theoretical value. The obtained compact structure secures high physical, mechanical, and operating characteristics of the finished product.
The wear behaviour investigation of sliding bearings with a designed testing machine
Abstract In this study, firstly a new wear testing machine was designed and produced in the university in order to investigate the wear behaviour of conventionally used sliding bearing alloys. Secondly, the wear tests of these bearings were performed by using this new machine. Three types of specimens’ wear behaviours were tested in this constructed machine. These were tin bronzes called RB-1 and RB-7 and tin-based lead bronze called RB-4. The wear tests were performed under 10, 20 and 40 N loads with 0.5 m/s sliding speed by using ring shaped specimens. During the experiments, these specimens are put in their location in the test machine and tightened and then vertically loaded against the mile located at the center of the motor. When the experiment was started the mile turns and a force occurs to put up with the friction occurred between mile and ring interface. This force creates a moment along the mile axis and tries to turn the specimen. As a result, a deflection was observed in a plate located on the top of the machine and it is recorded by means of a transducer as a voltage (V). These data were recorded in every 10 s and stored in a data acquisition card inside the computer. The experiments were conducted for 2 h. Having finished the tests, the weight losses of the specimens were measured, the coefficient of friction values were calculated, optical and SEM investigations were performed and finally the wear behaviour of conventionally used sliding bearing alloys was characterized.