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Sensing element is one of the main parts of a micromechanical accelerometer. It determines a lot of parameters of the whole device. Its design flow is a complex process including the steps from the analysis of technical and technological requirements to testing the manufactured devices. Testing is one of the most important steps because it allows not only getting the final characteristics of the chip, but also verifying and specifying the mathematical model of the sensing element for future designs. The paper presents the results of micromechanical accelerometer sensing element testing. Special attention is given to the steps of wafer-level testing and testing with an integrated circuit in the accelerometer.

The history of development of titanium alloys in Russia is presented. Structural and high-temperature titanium alloys, and alloys with intermetallic reinforcement are considered. The effect of chemical composition and structure on the properties of alloys is analyzed. The treatment process is described. Examples of the use of titanium alloys in various branches of Russian industry are presented.

Mechanical and process properties of widely used domestic structural titanium pseudo-alpha-alloys are studied. The Ti-Al-Mn system is chosen as a base for creating commercial titanium alloys of series OT4-0, OT4-1, OT4, etc. The developed titanium alloys guarantee ultimate rupture strength of 600 - 1100 MPa and possess satisfactory ductility in cold and hot plastic deformation. Experience in the use of alloys of this class in the aircraft and spacecraft industries is analyzed. In order to meet the international unification of titanium alloys the possibility of replacing manganese in pseudo-alpha-titanium alloys by vanadium is studied and documentation for realizing this replacement is created.

This article reports on the development and industrial use of production processes that employ high-temperature isothermal stamping to make disks for gas-turbine engines (GTEs) and other parts composed of hard-to-deform heat-resistant heterophase alloys of nickel and titanium. Mastering the production of semifinished products for GTE disks required the solution of a multifaceted problem – develop thermomechanical regimes for the alloys’ deformation that will make use of superplasticity, create effective protective-lubricant coatings, develop ultra-heat-resistant stamping materials that will be very durable in air, and design energy-efficient equipment for isothermal stamping. The technologies that have already been developed have been used to master the production of economical high-quality stampings made of hard-to-deform ultra-heat-resistant alloys that would be difficult or impossible to make by traditional technologies.

A titanium alloy hardened by cold working is described. An effective technology for large-scale production of parts from this alloy (bolts, screws, rivets, etc.) is suggested. Its physical and mechanical properties, structure, and phase transformations under heat treatment and cold deformation are studied. It is shown that the alloy and the method for fabricating parts from it are very efficient.

The growing interest in materials for the production of compressors for large aircraft engines working at 300-350 deg C has made it possible to estimate anew the possibilities of using aircraft structural titanium alloys for this purpose instead of high-temperature alloys. The aim of the present work consisted of determining the possibility of using high-strength Ti alloys for the production of large engine disks and blades working at 300-350 deg C and developing new modifications of material for these purposes. Alloy studied: VT22. VT37 and VT3-1 are also discussed.

A classification of β-titanium alloys based on a structural factor and reflecting the special features of physical, mechanical, and technological properties of each group is suggested.[PUBLICATION ABSTRACT]

Creation of titanium-base high-strength high-temperature alloys is of great scientific interest. Alloy VT22 additionally alloyed with carbon or boron, or simultaneously alloyed with carbon and boron is considered, with the aim of estimating the effect of the degree of dispersity, shape, and uniformity of distribution of intermetallic phases (titanium carbides and borides) on the combination of physical and mechanical properties and the structure of titanium alloys with the intermetallic type of hardening. The test rods were fabricated by traditional (hot deformation of the ingot) and granule (hot isostatic pressing of granules hardened from the melt) methods. The granule process is shown to provide substantially finer segregations of intermetallic phases and their more uniform distribution in the structure, which results in an increase in the high-temperature and conventional strengths and in the creep resistance of the alloy.

Alloy VT22 is used for studying the regular features of formation of recrystallized (grain) structure in die-formed preforms of titanium alloys of the transition class with coefficient of β-stabilization K^sub β^ = 1.0 - 1.3 in thermomechanical treatment involving deformation under isothermal conditions. The temperature and rate regimes of isothermal die forming and modes of thermomechanical treatment with the use of static, spontaneous, and dynamic recrystallization are determined with the aim of providing a controlled structure with β-grains 10 - 100 μm in size. It is shown that the formation of a recrystallized structure with b-grains 10 - 30 μm in size in deformed semiproducts from alloy VT22 makes it possible to raise the fracture toughness K^sub Ic^.[PUBLICATION ABSTRACT]

The creation of high-strength heat-resistant alloys based on titanium is of great scientific interest. Double-phase titanium (α+β) alloys are widely used at present. The alloying sets for these alloys are mainly developed with the purpose of increasing their strength and heat resistance by solution strengthening of the phases with substitutional elements. However, the increasing strictness of the requirements on the level of their mechanical properties makes it necessary to create titanium alloys that, can be strengthened by the segregation of an intermetallic phase or chemical compounds. An important problem in the development of such alloys is the choice of the optimum composition and the attainment, of the requisite dispersity and uniformity of distribution of segregations of strengthening phases in the structure. In this connection, carbon and boron, poorly soluble in titanium and forming independent carbide and boride segregations, are of some interest as alloying additives to these alloys.[PUBLICATION ABSTRACT]