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1.
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.
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2.
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.
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3.
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.
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4.
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.
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5.
1.  An industrial pressing and ejection unit has been designed and constructed for the production of long filter element compacts from metal powders.
2.  The unit is distinguished by its simplicity, reliability, and high output rate.
3.  As a result of the development of this unit it is now possible for the first time to employ in the Soviet Union a horizontal broaching machine for pressing metal powders.
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6.
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.
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7.
1.  The work described has shown that the difference in structure between particles of different sizes is preserved in sintered blanks.
2.  Steel blanks acquire a homogeneous structure after forging with a reduction of 80–90%.
3.  With rise in the oxygen content of powders the mechanical and cutting properties of sintered high-speed steels sharply fall.
4.  Vacuum heat treatment almost completely reduces surface oxide films on the particles of high-speed steel powders, enabling properties to be obtained similar to those of steel produced by orthodox techniques.
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8.
1.  It is shown that salt baths can be successfully employed in the heat treatment of sintered materials.
2.  Suitable bath compositions are recommended for heating sintered materials for quenching (75% BaCl2 + 25% NaCl) and for their tempering (50% KNO3 + 50% NaNO2).
3.  Optimum conditions are recommended for the heat treatment of ZhGr1.0-type sintered materials involving the use of salt baths (Table 1).
4.  The tensile strength and hardness of the material investigated has been found to grow 1.5–2.5 times as a result of heat treatment.
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9.
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.
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10.
1.  The strength with which a coating of chromium-nickel spinel adheres to an OT-4 titanium alloy substrate lies in the range 1.15–1.40 kg/mm2. Preheating the surface to be coated to 450°C increases the adhesion of the coating by 25–30%.
2.  The adhesion of a coating to its substrate begins to decrease appreciably after 10 thermal cycles.
3.  An 80% Ni-20% Cr alloy undercoat has no effect upon the adhesion of a spinel coating and adversely affects its thermal fatigue resistance.
4.  The degree of blackness (coefficient of absorption) of a spinel coating is 0.94–0.95.
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11.
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.
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12.
1.  In the sintering of mixtures of metal powders forming alloys with a peritectic constitution diagram the composition dependence of the volume changes experienced by the alloys in the two-phase field has a minimum.
2.  In the sintering of mixtures of metal powders forming alloys with unstable chemical compounds and a constitution diagram with a two-phase peritectic-type field the composition dependence of shrinkage has a minimum within the limits of that field.
3.  The formation of an unstable intermetallic compound during the sintering of mixtures of metal powders gives rise to no special volume effects.
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13.
1.  A study was made of the microhardness and the temperature dependence of the thermal conductivity, electrical resistivity, thermo-emf, and coefficients of thermal expansion of two ternary compounds in the system Ti-Al-C.
2.  It was established that the conductivity of these compounds has a metallic character.
3.  From the microhardness and coefficient of thermal expansion values obtained it can be concluded that the atomic linkage forces in these compounds grow in the order Ti2AlC <>3AlC < tic.=">
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14.
1.  A study was made of the sintering of aluminum dust compacts with the aim of determining the optimum conditions for the formation of a skeletal structure in the resultant material.
2.  On the basis of data concerning density, electrical resistivity, and structure variations it was established that a skeletal alumina structure can be obtained in compacts produced both by cold pressing and subsequent sintering and by hot pressing.
3.  A study of the mechanical properties of SAP materials showed that their heat resistance is substantially increased by the formation of a skeletal alumina structure.
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15.
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.
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16.
1.  The velocity of propagation of ultrasonic vibrations can be used as a measure of the strength of as-sintered and plastically worked porous metals.
2.  The strength of re-pressed specimens only slightly exceeds that of specimens of the same density produced by single pressing and sintering. This is due to the simultaneous manifestation of a strengthening induced by the work-hardening of the material during plastic working and a strength loss caused by the presence of macroscopical crevice-like defects.
3.  By measuring the velocity of propagation of USV it is possible to calculate the strength of an unworkhardened material having the same structure as a worked porous material.
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17.
1.  Small-sized extensometers have been developed for a wide range of strains in tension and torsion.
2.  A study was made of the strength, ductility, and elasticity characteristics of two types of sintered material in tension and torsion. In the as-sintered condition the two types of material were found to have almost identical strength properties. In the heat-treated condition the strength properties of type II proved to be superior to those of type I, and consequently the former type should be chosen for parts intended for operation under static load conditions.
3.  Impact tests were carried out on notched and unnotched specimens. In both the as-sintered and heat-treated conditions type I was found to surpass type II in impact strength. It follows therefore that parts intended for service involving shock loads should be made in type I material.
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18.
1.  Examinations with a scanning electron microscope have yielded results supporting the existing hypotheses concerning the mechanism of growth of pyronitride coatings during gaseous-phase deposition.
2.  A study was made of the morphology of fibers coated with zirconium pyronitride. It is shown that such coatings have the columnar structure characteristic of pyrolytic deposits.
3.  It is demonstrated that the thickness of a coating applied by the gaseous-phase deposition technique can be accurately determined by calculation.
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19.
1.  Flake iron powders rolled with reductions of 60–80% exhibit no pronounced crystallographic texture.
2.  Because of the lack of favorable texture in flake powders there is little to be gained from orienting their particles in a magnetic field during the pouring operation.
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20.
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.
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