Diamond Grinding Technology of Flexural Strength Test Pieces of Super hard, Brittle, Composite-ceramic Materials and Technological Equipment

At the present stage of the revolutionary development of technologies, scientists from the leading countries of the world are working intensively to create qualitatively new materials whose physical-mechanical, electrical, thermal or other properties far exceed the basic constructions, armament or other metals used. Such materials are surface, brittle, composite ceramic materials (based on oxide and carbide ceramics, state-of-the-art surface compositions, polycrystalline diamond + Si  SiC and etc.). A progressive process for diamond grinding test samples from composite ceramic materials to determine the bending strength is discussed. The proposed technological process is based on an original and effective method for polishing the flat surfaces of articles made of difficult-to-process and composite materials - low-temperature precision grinding (LPG). Based on the results of many years and multilateral studies in the field of diamond processing of various non-metallic, composite and ceramic materials, optimum conditions for diamond polishing of mentioned materials have been determined and recommended. Technological equipment and equipment for processing composite and ceramic materials are also disclosed.

Structure and Magnetodielectric Properties of Composite Ceramics Based on Lead Ferroniobate

In this research, the structural, electrodynamic, and magnetodielectric properties of composite ceramic materials based on lead ferroniobate Pb(Fe0.5Nb0.5)O3 have been studied. The experimentally obtained temperature and frequency dependences of the dielectric constant indicate the presence of a low-temperature polar state, large values of the dielectric constant in the microwave range, and high electrical conductivity of the materials studied.

Modernization of the System for Measuring Cutting Forces on the Basis of UDM Dynamometer Series

The purpose of the research was to analyze the existing systems for measuring forces during machining of parts on metal-cutting machine tools, and to consider the options for using both specialized ready-made solutions and dynamometer heads of the UDM series as measuring transducers. The study shows the drawbacks of the well-known general-circuit solutions for the modernization of these dynamometers, associated with the need to use heterogeneous sets of amplifying and transforming equipment. We propose low-budget solutions to improve the accuracy and reliability of measurements, to control and record measurement results in a modern software environment using virtual instruments. As a result of the study, we implemented hardware and software methods for processing measurement information, accompanying experimental studies in real time. The universal scalable systems developed for measuring moments and cutting forces are used both during academic research work and educational process of the university The work is carried out under the program "Scientific and scientific-pedagogical personnel of innovative Russia", event: 1.2.1. Scientific studies are done by research teams under the guidance of doctors of science; the research area is "Creation and processing of composite ceramic materials", the project is "Improving the efficiency of mechanical and abrasive machining of parts made of composite ceramic materials"

Porous Hydroxyapatite/Strontium Oxide Composite Ceramic Preparation and Properties of Biomaterials

Objective: This study aims to added strontium to hydroxyapatite (HA) through physical means and prepare porous composite ceramic materials with good mechanical properties to further improve the osteogenesis-inducing effect of bone repairing materials. Methods: The composite powders of strontium oxide/hydroxyapatite (SrO/HA) was obtained by mechanical milling. Then, porous SrO/HA composite ceramics were prepared by spark plasma sintering. The composition, structure and morphology of these porous composite ceramic materials were characterized using X-ray diffraction and scanning electron microscope, and the porosity and mechanical properties were tested. Results: Porous composite ceramic materials with clear composition were prepared, and obvious porous structures were observed. Conclusion: After ball milling, a replacement reaction occurred in the prepared porous SrO/HA composite powder with different SrO contents, part of Ca2+ in HA (Ca10[PO4]6[OH]2was replaced by Sr2+, and merely a small amount of powder underwent decomposition during sintering at 1,100 °C. Under an electron microscope, the pore characteristics of the composite ceramic materials were obvious, the distribution was uniform, and the connectivity was good. The compressive strengths of these materials ranged within 2–8 MPa. This shows that the strontium element can also be doped by physical means, and that the obtained porous SrO/HA composite ceramic material has good pore characteristics and good application potential in bone repair.