Composites were obtained in the in SiC-SiAlON and Al2O3-SiAlON system. Physical-chemical processes going on at the obtaining of SiALON within the range of 800°C - 1500°C were studied. Charge compositions and...Composites were obtained in the in SiC-SiAlON and Al2O3-SiAlON system. Physical-chemical processes going on at the obtaining of SiALON within the range of 800°C - 1500°C were studied. Charge compositions and sintering regime were selected. It was proved that X-SiALON was obtained at the sintering of kaolin-aluminum powder at 1500°C, while β-SiALON was formed at the sintering of SiC-Aluminum powder, silicium and Al2O3-aluminum powder, silicium at 1500°C. Corrosion properties of the materials were studied. Investigations were performed by the methods of X-Ray structural and microscopical analysis.展开更多
Experimental works have been conducted the objective of which was to improve mechanical properties of boron carbide by introduction of doping elements into the system. Titanium and Zirconium were selected as doping el...Experimental works have been conducted the objective of which was to improve mechanical properties of boron carbide by introduction of doping elements into the system. Titanium and Zirconium were selected as doping elements, which were introduced into the system in the form of TiB2 and ZrB2. Four types of boron carbide-titanium and zirconium mixture with various titanium and zirconium diboride content were used in experiments. Optimal process parameters, as well as doping elements concentration, necessary to provide required high mechanical parameters in the composite were defined.展开更多
The object of the research was to study the composite received in impure nitrogen medium from silicon carbide, silicon and refractory clay mixture. With X-ray diffraction, petrographic and electron microscope methods ...The object of the research was to study the composite received in impure nitrogen medium from silicon carbide, silicon and refractory clay mixture. With X-ray diffraction, petrographic and electron microscope methods the chemical processes happening at burning of the mentioned mixture in technical nitrogen medium and the kind of received binder, phase composition and basic properties are studied. It is stated that silicon carbide composite with complex binder is received, the main phases being: Si2ON2, 3Al2O3· 2SiO2 and SiO2. SiC-Al2O3 composite is also received and studied. Water and acid resistance of composites (H2SO4, r—1.84 g/sm3) and resistance to nonferrous metals and slag are studied. The received composites can be used for production of protective envelope of thermocouple for measuring of temperature of ferrous and nonferrous metals at high temperatures.展开更多
Goal: Low wolfram-containing cutting composite was obtained by fusion of titanium carbonitride and high melting temperature binding metallic phase. Method: The composite was obtained via compaction and further sinteri...Goal: Low wolfram-containing cutting composite was obtained by fusion of titanium carbonitride and high melting temperature binding metallic phase. Method: The composite was obtained via compaction and further sintering in vacuum furnace at 1600°C under 10<sup>-3</sup> Pa pressure. Phase analysis was performed on X-ray apparatus “DRON-3”;microstructure was determined by electron microscope NANOLAB-7, microhardness by MUCKE-mark microhardness meter;relative resistance of cutters was evaluated at similar modes of cutting according to distances they passed;experiments were carried out on turning lathe. Results: Physical-mechanical characteristics of the obtained composite are: σ<sub>bend</sub>, = 1000 - 1150 MPa, σ<sub>bend1000</sub>°C = 600 MPa, HV = 14 GPa;HV<sub>1000</sub>°C = 6.5 GPa. High speeds of cutting and high temperatures resistance of cutters made by the obtained composites exceeds 1.5 - 2-folds that of cutters made of the known BK8 and KNT20 hard alloys. Conclusion: Its application is recommended in hot steel treatment by cutting, for removal of the so-called burrs, as well as in steel treatment by cutting during pure and semi-pure operations. It can also be used in jet engines, chemical industry apparatuses, electric-vacuum devices, in industry of responsible details of rockets, nuclear reactors, flying apparatuses.展开更多
文摘Composites were obtained in the in SiC-SiAlON and Al2O3-SiAlON system. Physical-chemical processes going on at the obtaining of SiALON within the range of 800°C - 1500°C were studied. Charge compositions and sintering regime were selected. It was proved that X-SiALON was obtained at the sintering of kaolin-aluminum powder at 1500°C, while β-SiALON was formed at the sintering of SiC-Aluminum powder, silicium and Al2O3-aluminum powder, silicium at 1500°C. Corrosion properties of the materials were studied. Investigations were performed by the methods of X-Ray structural and microscopical analysis.
文摘Experimental works have been conducted the objective of which was to improve mechanical properties of boron carbide by introduction of doping elements into the system. Titanium and Zirconium were selected as doping elements, which were introduced into the system in the form of TiB2 and ZrB2. Four types of boron carbide-titanium and zirconium mixture with various titanium and zirconium diboride content were used in experiments. Optimal process parameters, as well as doping elements concentration, necessary to provide required high mechanical parameters in the composite were defined.
文摘The object of the research was to study the composite received in impure nitrogen medium from silicon carbide, silicon and refractory clay mixture. With X-ray diffraction, petrographic and electron microscope methods the chemical processes happening at burning of the mentioned mixture in technical nitrogen medium and the kind of received binder, phase composition and basic properties are studied. It is stated that silicon carbide composite with complex binder is received, the main phases being: Si2ON2, 3Al2O3· 2SiO2 and SiO2. SiC-Al2O3 composite is also received and studied. Water and acid resistance of composites (H2SO4, r—1.84 g/sm3) and resistance to nonferrous metals and slag are studied. The received composites can be used for production of protective envelope of thermocouple for measuring of temperature of ferrous and nonferrous metals at high temperatures.
文摘Goal: Low wolfram-containing cutting composite was obtained by fusion of titanium carbonitride and high melting temperature binding metallic phase. Method: The composite was obtained via compaction and further sintering in vacuum furnace at 1600°C under 10<sup>-3</sup> Pa pressure. Phase analysis was performed on X-ray apparatus “DRON-3”;microstructure was determined by electron microscope NANOLAB-7, microhardness by MUCKE-mark microhardness meter;relative resistance of cutters was evaluated at similar modes of cutting according to distances they passed;experiments were carried out on turning lathe. Results: Physical-mechanical characteristics of the obtained composite are: σ<sub>bend</sub>, = 1000 - 1150 MPa, σ<sub>bend1000</sub>°C = 600 MPa, HV = 14 GPa;HV<sub>1000</sub>°C = 6.5 GPa. High speeds of cutting and high temperatures resistance of cutters made by the obtained composites exceeds 1.5 - 2-folds that of cutters made of the known BK8 and KNT20 hard alloys. Conclusion: Its application is recommended in hot steel treatment by cutting, for removal of the so-called burrs, as well as in steel treatment by cutting during pure and semi-pure operations. It can also be used in jet engines, chemical industry apparatuses, electric-vacuum devices, in industry of responsible details of rockets, nuclear reactors, flying apparatuses.
