Spectral analysis of the structure of ultradispersed diamonds

The structure of ultradispersed diamonds (UDD) is studied by spectral methods. The presence of diamond crystal phase in the UDD is found based on x-ray analysis and Raman spectra. The Raman spectra also show sp2- and sp3-hybridized carbon. Analysis of IR absorption spectra suggests that the composition of functional groups present in the particles changes during the treatment

МЕТРОЛОГИЧЕСКОЕ ОБЕСПЕЧЕНИЕ ТЕМПЕРАТУРНЫХ ИЗМЕРЕНИЙ: СОСТОЯНИЕ И ПРОБЛЕМЫ

The specifications of equipment produced by CAS «BMC» for metrological provision of temperature measurements are presented: low temperature thermostat «Cryostat», thermostatic device «Thermostat-A3», reference thermometer «ITE»,  measuring-calculating complex  «IST-M16». Some problems  of normative documents regulating temperature measurements are discussed. New formula approximating temperature vs. thermoelectromotive for type M thermocouple is proposed.Представлены характеристики оборудования производства ЗАО «БМЦ» для метрологического обеспечения температурных измерений: термостат низкотемпературный  «Криостат»,  устройство  термостатирующее  измерительное «Термостат-А3», измеритель температуры эталонный «ИТЭ», комплекс измерительно-вычислительный «ИСТ-М16». Обсуждены проблемы нормативной документации, регламентирующей температурные измерения, и предложена новая формула, аппроксимирующая зависимость температуры от термоэдс для термопары типа М

ОПРЕДЕЛЕНИЕ АДГЕЗИОННОЙ ПРОЧНОСТИ Mo-Ti-N И Mo-Сu-N ПОКРЫТИЙ НА УСТАНОВКЕ «СКРЕТЧ-ТЕСТЕР»

The new «scratch-tester» device for measurement of adhesion strength of coatings is presented. The device has a number of advantages as compared with known analogues – the expanded range of investigated sample sizes and more simple procedure of sample positioning, more precise measurement of scratching length, additional manner of registration of coating destruction or tearing off instant on the base of friction force. The device was used for investigation of Mo-Ti-N and Mo-Сu-N coatings on carbide cutting insert. It was found that Мо-Ti-N coatings have five times greater adhesion strength as compared with MoCu-N coatings.Разработана установка («скретч-тестер») для определения адгезионной прочности покрытий. Установка имеет ряд преимуществ по сравнению с известными аналогами – расширенный диапазон размеров исследуемого образца и более простая процедура его позиционирования, более точное измерение длины скрайбирования, дополнительный способ регистрации момента разрушения или отрыва покрытия по силе трения. Установка использована для исследования покрытий Mo-Ti-N и Mo-Сu-N на твердосплавных пластинах, и установлено, что покрытия Мо-Ti-N имеют в пять раз большую адгезионную прочность, чем покрытия Mo-Cu-N.

METROLOGICAL PROVISION OF TEMPERATURE MEASUREMENTS: STATUS AND PROBLEMS

The specifications of equipment produced by CAS «BMC» for metrological provision of temperature measurements are presented: low temperature thermostat «Cryostat», thermostatic device «Thermostat-A3», reference thermometer «ITE»,  measuring-calculating complex  «IST-M16». Some problems  of normative documents regulating temperature measurements are discussed. New formula approximating temperature vs. thermoelectromotive for type M thermocouple is proposed

Spectral analysis of the structure of ultradispersed diamonds

The structure of ultradispersed diamonds (UDD) is studied by spectral methods. The presence of diamond crystal phase in the UDD is found based on x-ray analysis and Raman spectra. The Raman spectra also show sp2- and sp3-hybridized carbon. Analysis of IR absorption spectra suggests that the composition of functional groups present in the particles changes during the treatment

Wear-resistant metal-carbon composite coating

Carbon coatings containing a metallic component (zirconium, tantalum) were deposited with ion assistance on AISI M2 steel samples using a SVETLYACHOK source. The coatings were studied by Auger electron spectroscopy (AES), transmission electron microscopy (TEM), Raman spectroscopy (RS) and pin-on-disc tribological tests. The results have shown that the carbon coatings contain up to 20 at.% of the metallic component. These coatings have an amorphous structure with sp3-type bonds. The presence of the coating on the surface of AISI M2 steel reduces the friction coefficient by a factor of five under the tribological conditions investigated. It is found that the tribological properties of the coatings deposited with the assistance of metal ions are significantly better than those coatings deposited with assistance of carbon ions. The latter coatings had carbon atoms with mixed sp3-sp2 bonds. The deposited composite carbon coatings are stable at a temperature of 100°C and allow a twofold improvement in the lifetime of fuel pump rods. (C) 2000 Elsevier Science S.A. All rights reserved.This work has been supported by the Belarussian Fund of Fundamental Research under grant no. T-98 323. The authors are grateful to Ms Marta Brizuela (INASMET) for conducting tribological tests.Peer reviewe

MEASUREMENT OF ADHESION STRENGTH OF Mo-Ti-N AND Mo-Сu-N COATINGS USING «SCRATCH-TESTER» DEVICE

The new «scratch-tester» device for measurement of adhesion strength of coatings is presented. The device has a number of advantages as compared with known analogues – the expanded range of investigated sample sizes and more simple procedure of sample positioning, more precise measurement of scratching length, additional manner of registration of coating destruction or tearing off instant on the base of friction force. The device was used for investigation of Mo-Ti-N and Mo-Сu-N coatings on carbide cutting insert. It was found that Мо-Ti-N coatings have five times greater adhesion strength as compared with MoCu-N coatings

High speed steel structure studing after various high intensity ion-plasma treatments

The influence of compressive plasma flow (CPF) treatment on structure of AlSI М2 steel was investigated and was compared with the influences of other known high intensive techniques such as high current ion implantation (HCII) and plasma immersion ion implantation (PIII) of nitrogen. The structure of steel forming during HCII is more stable and is a superposition of martensite, hardening carbides, carbonitrides and small quantity of austenite. The structure of thick (about 30 µm) surface layer of steel undergoes great changes after CPF - decay of main hardening M6C carbide and formation of expanded austenite doped by nitrogen and alloying elements of steel. Pill forms similar thinner modified layer

High speed steel structure studing after various high intensity ion-plasma treatments

The influence of compressive plasma flow (CPF) treatment on structure of AlSI М2 steel was investigated and was compared with the influences of other known high intensive techniques such as high current ion implantation (HCII) and plasma immersion ion implantation (PIII) of nitrogen. The structure of steel forming during HCII is more stable and is a superposition of martensite, hardening carbides, carbonitrides and small quantity of austenite. The structure of thick (about 30 µm) surface layer of steel undergoes great changes after CPF - decay of main hardening M6C carbide and formation of expanded austenite doped by nitrogen and alloying elements of steel. Pill forms similar thinner modified layer