共查询到20条相似文献，搜索用时 15 毫秒
1.
I. Ya. Dzykovich V. V. Panichkina V. V. Skorokhod L. I. Shaiderman 《Powder Metallurgy and Metal Ceramics》1976,15(2):151-153
| 1. | A study, based on electron probe microanalysis, was made of the distribution of the components in the systems W/Cr and W/Pd-Cr after various heat treatments. |
| 2. | It was established that coating W specimens with palladium substantially intensifies diffusion processes. In specimens without palladium coatings no interdiffusion of the two components (W and Cr) is observed even in the course of prolonged annealing. |
| 3. | It is shown that, in the case of palladium-plated tungsten specimens, the width of the resultant diffusion zones depends on the heat treatment conditions. In the work described the diffusion zone was 15. wide after 30 min of annealing and 30 wide after 12 h. |
| 4. | It was found that palladium, being a surface active element, enriches the surface layers of specimens, giving rise to the formation of complex palladium-chromium coatings. |
2.
O. A. Katrus A. V. Aleshina Z. P. Bikarevich 《Powder Metallurgy and Metal Ceramics》1976,15(7):546-548
| 1. | It is shown that the geometric factor affects the reduction of oxides in strip during sintering. |
| 2. | The duration of sintering necessary for preventing the development of hydrogen blight in densified strip during sensitizing annealing in hydrogen has been determined. |
3.
| 1 | At 150°C and in the temperature ranges 250–350 and 500–650°C the physicomechanical properties of the compound Ti3Al and its alloys vary with temperature in an irregular manner. In view of the fact that these anomalies exhibit no hysteresis on heating and cooling and also that the high-temperature modification cannot be preserved in an overcooled condition, the phenomena observed may be regarded as manifestations of isomorphic tr ans for mations. |
| 2 | The nature of the isomorphic transformations taking place in the compound Ti3Al and its alloys in the temperature ranges 250–350 and 500–650°C is linked with changes in the SWASC in the titanium and aluminum sublattices and s(p)d electron exchange between the atoms in the aluminum and titanium sublattices during the thermal excitation of their outer electron subshells. |
| 3 | The variation of the physical properties of the compound at temperatures above 800°C is attributable to the nucleation of regions with a degree of long-range order<1, which=" ends=" at=" a=" temperature=" close=" to=" 1080°c=" with=" the=" polymorphic="> 2 phase solid solution. |
4.
V. S. Viderman G. V. Zemskov A. I. Shestakov A. S. Sin'kovskii 《Powder Metallurgy and Metal Ceramics》1976,15(4):290-292
| 1. | It was established that diffusion coatings can be produced on boron carbide by gaseous-phase chemicothermal treatment in chromium and titanium halides, and a study was made of the effects of some parameters upon the depth and phase composition of the resultant diffusion layers. |
| 2. | Use of ammonium chloride as an activator of the process leads to the deposition of chromium and titanium nitrides. |
| 3. | The diffusion coating produced by chromizing contains chromium borides, carbides, and nitrides, while the coating produced by titanizing consists of a solid solution based on the cubic TiN structure with a parametera=4.28 Å. Coatings of such phase compositions are capable of reducing the reaction of boron carbide with metallic binders. |
5.
Yu. V. Razovskii 《Metallurgist》1995,39(3):49-51
| 1. | Mining rent, although having some specific features related to its source, is closely connected with financial rent and is similar in its economic nature to ground rent, which makes it possible to determine mining rent on the basis of macroeconomic financial parameters. |
| 2. | The infinite variety of the conditions determining the amount of mining rent makes it necessary to take into account the maximum possible number of criteria for its differentiation, thus making much more difficult the calculation and the comparison of the size of the mining rent for different mining enterprises, especially those engaged in mining different kinds of mineral resources. |
| 3. | The use of the proposed model for calculating mining rent based on comparison of the value of the optimized profit of a mining enterprise, cleared of the part of the profit that is not related to the mining and primary processing of mineral resources, and the prevalent level of the bank interest rate related to the cleared cost of the capital assets of the enterprise allows one to take into account integrally the numerous differentiation conditions for mining rent and the risk of possible nonreturn of an investment connected with the specific features of the mining industry as the object of investments. |
6.
| 1. | It is shown that the ratio of the mean pore size of a sintered sheet material produced from a non-spherical powder to the mean powder particle size diminishes with increase in starting particle size. Kozeny's formula cannot be used for calculating the mean pore sizes of sheet materials other than those of 20–30% porosity made from a 20–40 powder fraction. |
| 2. | It has been established that in the power-type relationship between the mean pore size of a sheet material and its porosity the exponent grows with increase in powder particle size. Deviations from the power-type relationship exhibited by sheets of more than 40% porosity produced from coarse powder fractions are linked with changes in the pore tortuosity factor. |
7.
V. F. Lykova V. P. Doronicheva Zh. I. Dzneladze R. P. Shchegoleva 《Powder Metallurgy and Metal Ceramics》1976,15(11):850-853
| 1. | A quantitative metallographic analysis, made with a Quantimet-720 microscope, of nonmetallic inclusions in sintered and worked Fe-Al alloys has shown that with rise in aluminum content from 2 to 10% the volume content of inclusions and their total number grow. |
| 2. | Most of the nonmetallic inclusions in the sintered Fe-Al alloys investigated were identified as -A12I3. |
8.
G. V. Samsonov L. A. Gaevskaya A. A. Adamovskii 《Powder Metallurgy and Metal Ceramics》1976,15(1):71-74
| 1. | A study was made of the relationship between the ductility of titanium, niobium, and tungsten carbides and the amount of material removed from Groups IV–VI refractory transition metals during abrasive polishing and also of the relationship between the surface finish acquired by these metals during polishing and their mechanical properties. |
| 2. | It was established that, for all the metals investigated, the greater the ductility of the abrasive the greater is the amount of metal removed. |
| 3. | The amount of material removed from refractory transition metals during polishing with each of the carbides selected is determined by their crystal lattice rigidity (measured by the quantity m2), decreasing with increase in lattice rigidity. |
| 4. | The surface roughness produced by polishing grows on passing from Group IV to Group V metals and then diminishes for Group VI metals. Such a variation of surface roughness is a consequence of the dual nature of atomic linkage in these metals. |
9.
M. N. Nasonova V. S. Galinker V. A. Gorbatyuk L. L. Klimuk 《Powder Metallurgy and Metal Ceramics》1976,15(2):83-85
| 1. | Tripolyphosphate electrolytes can be employed for the production of tin bronze powders whose composition and particle size can easily be controlled by changing deposition conditions. |
| 2. | The basic relationships between electrolysis parameters and alloy composition and cathodic current efficiency established in a study of the electrodeposition of dense bronze coatings are observed also in the production of electrolytic powdered alloys from TPP electrolytes. |
| 3. | The optimum conditions for the preparation of tin bronze powders from TPP electrolytes have been determined. The electrolyte compositions for the deposition of white and yellow bronze powders are (mole/liter) sodium TPP 0.55 each, copper sulfate 0.105 and 0.126, respectively, and tin chloride 0,035 and 0.014, respectively. The optimum process parameters are pH 6–8, t=30–40°C, Dc=15–25 A/dm2, electrolyte agitation. |
10.
O. B. Chevela A. S. Nagin A. G. Cherdakli V. N. Gadalov 《Powder Metallurgy and Metal Ceramics》1976,15(2):108-110
| 1. | In the deposition of a tungsten coating on a titanium substrate regions of chemical reaction are observed. In the deposition of an 80% Ni-20% Cr alloy coating by the plasma-spraying process adhesion is purely mechanical in character. |
| 2. | It has been established that the amount of tungsten in the zones of chemical reaction is a function of the spraying range. |
11.
O. N. Ryabinina A. I. Raichenko A. D. Verkhoturov E. A. Shavlovskii L. A. Kotlyarenko 《Powder Metallurgy and Metal Ceramics》1976,15(9):703-705
| 1. | It has been established that a punch electrode contact surface of Class 4–5 finish provided with a coating with a coverage of 60% adheres to metal powders during their electric discharge sintering. |
| 2. | It is shown that titanium carbide and chromium carbide diffusion coatings on 3Kh2V8F steel reduce the extent of interaction between punch electrodes and copper, aluminum, and titanium powders during their EDS compared with coatings applied by the electric spark and detonation processes. In addition, diffusion coatings adhere most strongly to a steel substrate. |
| 3. | The interaction is influenced to a large extent by the nature of the metal powder. Of the three powders investigated, Ti, Al, and Cu, titanium powder reacts most strongly, and copper least strongly, with punch electrodes. |
| 4. | In contact with copper powder the best performance is given by a titanium carbide coating. In the EDS of aluminum powder under a prepressing pressure of less than 2 tons/cm2 local passage of electric current is observed leading to welding between the punch electrodes and the sintered specimen; consequently, in the sintering of aluminum powder with punch electrodes coated with chromium carbide and titanium carbide prepressing pressures of not less than 2 tons/cm2 should be employed. TIC coatings are unsuitable for operation in contact with titanium powder. |
12.
| 1. | Nonlinear equations have been derived describing the dynamics of the operation of the press-container system. |
| 2. | On the basis of these equations a model for an analog computer has been constructed enabling the dynamic characteristics of the pressing process in the press-container system to be determined. |
| 3. | The operation of the press-container system is characterized by stability and linear variation of parameters during pressing. |
| 4. | The rate of pressure rise depends to a large extent on the parameters of the container and the volume and coefficient of compressibility loss of the part being pressed. |
13.
| 1. | A study was made of the synthesis of finely divided ferrite materials. |
| 2. | A relationship was found to exist between the fineness of a ferrite powder produced by the coprecipitation technique and the concentration of the starting mixture. |
| 3. | It is shown that drying under restricted air supply conditions with agitation activates ferrite powders and decreases their particle size. |
| 4. | It has been established that the presence of Bi, Mo, and Ge microalloying additions activates the sintering of a magnesium-manganese ferrite. |
14.
V. S. Klimenko V. G. Skadin S. Yu. Sharivker E. A. Astakhov A. I. Zverev 《Powder Metallurgy and Metal Ceramics》1976,15(11):841-843
| 1. | Methods have been developed for measuring the temperature and velocity of the gas stream in detonation spraying. |
| 2. | The time dependence of these parameters has been determined for the process of detonation spraying with an acetylene-oxygen mixture. |
| 3. | Analysis of the relations obtained shows that the dynamics of particles of the material being sprayed is controlled mainly by the gas flowing out of the barrel after the end of detonation. |
15.
I. I. Beloborodov A. I. Yuga N. D. Nazarenko L. F. Kolesnichenko N. I. Vlasko 《Powder Metallurgy and Metal Ceramics》1976,15(11):882-884
| 1. | The feasibility is demonstrated of producing Sitall-base porous skeletons. |
| 2. | Impregnation of a porous skeleton with a suspension of PTFE and graphite enables a composite material to be obtained possessing excellent antifriction properties. |
| 3. | The presence of a metallic filler in such a composite material increases its load-carrying capacity. |
16.
V. F. Funke A. I. Tyutyunnikov V. S. Makeev A. N. Pilyugin V. A. Shevchenko 《Powder Metallurgy and Metal Ceramics》1976,15(6):452-455
| 1. | A study was made of the effects of temperature and methane concentration on the rate of deposition of NbC and ZrC in an apparatus with a continuously circulating vapor-gas mixture consisting of a metal chloride, methane, hydrogen, and argon. |
| 2. | It is shown that in the temperature range 900–1100°C niobium carbide is deposited containing no free carbon. At a temperature of 1600°C and a methane:zirconium-tetrachloride volume concentration ratio below 0.7 zirconium carbide is deposited containing no free carbon. |
| 3. | An experimental apparatus, Kontur-1, has been constructed and tested which enables niobium and zirconium carbides to be deposited in a closed circuit with vapor-gas phase circulation. |
17.
| 1. | It has been established that titanium-carbide-steel materials containing copper additions experience precipitation hardening. |
| 2. | The addition of copper does not alter the optimum heat treatment temperatures for these materials. |
18.
A new unidirectional solidification (US) method to study gray cast iron was developed. It is based on the combination of the
classical Bridgman-type technique and the directional casting technique. By means of this method, it is possible to achieve,
among others, the following aims:
相似文献
| (a) | changes in chemical composition of the melt during the experiment without modifying G/R (G: thermal gradient and R: solidification rate); |
| (b) | US of modified (compacted/vermicular) gray-cast iron, avoiding equiaxal nucleation in front of the solid/liquid (S/L) interface; and |
| (c) | quenching of the S/L interface retaining the microstructure of the growing solid. |
19.
| 1. | It is shown that the elastic stress set up in VK15-hard-alloy/US-steel welds depends to a large extent on the geometry of the elements being joined. |
| 2. | Use of intermediate compensating linings up to 0.2 mm thick in 34NKMP Permalloy-type alloy appreciably reduces the elastic stress in the hard-alloy/steel weld zone. |
20.
S. Yu. Sharivker Ts. A. Kanevskaya E. A. Astakhov K. D. Modylevskaya 《Powder Metallurgy and Metal Ceramics》1976,15(2):157-158
| 1. | A study was made of the surface profile of a polished titanium plate after nickel powder had been deposited on it by the detonation spray-deposition process and the resultant coating stripped from it. |
| 2. | It is shown that detonation spray deposition results in the appearance of microroughness and waviness on the surface being coated. Both types of irregularity are linked with the formation of waves on the contact surface during the impact of particles on the basis metal and the simultaneous plastic deformation of the deposit and the basis. |