Nanoindentation Response of Ion-Irradiated Fe, Fe-Cr Alloys and Ferritic-Martensitic Steel Eurofer 97: The Effect of Ion Energy

Nanoindentation of ion-irradiated nuclear structural materials and model alloys has received considerable interest in the published literature. In the reported studies, the materials were typically exposed to irradiations using a single ion energy varying from study to study from below 1 MeV to above 10 MeV. However, systematic investigations into the effect of self-ion energy are still insufficient, meaning that the possibilities to gain insight from systematic energy variations are not yet exhausted. We have exposed pure Fe, ferritic Fe-9Cr, martensitic Fe-9Cr and the ferritic-martensitic reduced-activation steel Eurofer 97 to ion irradiations at 300°C using 1, 2 and 5 MeV Fe2+ ions as well as 8 MeV Fe3+ ions and applied nanoindentation, using a Berkovich diamond indenter, to characterize as-irradiated samples and unirradiated references. The effect of the ion energy on the measured nanoindentation response is discussed for each material. Two versions of a primary-damage-informed model are applied to fit the measured irradiation-induced hardening. The models are critically compared with the experimental results also taking into account reported microstructural evidence. Related ion-neutron transferability issues are addressed.

Progressive changes in crystallographic textures of biominerals generate functionally graded ceramics

Biomineralizing organisms are widely praised for their ability to generate structural materials with exceptional crystallographic control. While earlier studies highlighted near-to single-crystalline biominerals, complex polycrystalline features are more widespread yet...

Covalently integrated silica nanoparticles in poly(ethylene glycol)-based acrylate resins: thermomechanical, swelling, and morphological behavior

Nanocomposites integrate functional nanofillers into viscoelastic matrices for electronics, lightweight structural materials, and tissue engineering. Herein, the effect of methacrylate-functionalized (MA-SiO2) and vinyl-functionalized (V-SiO2) silica nanoparticles on the thermal, mechanical,...

CONCEPTION OF A “SILENT” MORTAR PROJECTILE. PART III – DESIGN AND STRENGTH CALCULATIONS

The paper deals with some selected elements of a designing process for a “quiet” mortar projectile. Basing on it a decision could be made if specifications of the design were met. Numerical computations have proved that it is possible to design a quiet 60 mm mortar projectile with the range of 1200 ÷ 1300 m and own mass 1.8 kg. Moreover, the strength calculations have proved that the projectile can be made of commonly used structural materials.

POLYMER COMPOSITE MATERIALS BASED ON POLYTETRAFLUOROETHYLENE FILLED WITH MODIFIED MONTMORILLONITE

Актуальность исследования состоит в том, что одними из перспективных конструкционных и функциональных материалов остаются полимерные композиты на основе политетрафторэтилена. Благодаря уникальным базовым свойствам он находит широкое применение во всех отраслях промышленности, прежде всего в качестве антифрикционных материалов для узлов трения. В условиях низких температур композиты на основе ПТФЭ являются наиболее перспективными триботехническими материалами для сохранения работоспособности техники и оборудования Севера и арктических регионов. Недостатком ПТФЭ являются низкая износостойкость, хладотекучесть, высокий коэффициент термического расширения, которые можно улучшить добавлением наполнителей.Целью работы является исследование влияния монтмориллонита марки Метамона®1Н1 на свойства и структуру политетрафторэтилена (ПТФЭ).В качестве полимерной матрицы использован политетрафторэтилен марки ПТФЭ марки ПН-90, ООО «Галополимер»,г. Пермь.В качестве наполнителя использован Монтмориллонит марки МЕТАМОН® 1Н1 – гидрофильная глина, представляющая очищенный природный Na+ - монтмориллонит.Введение активированного метамона в композиты позволяет повысить деформационно-прочностные характеристики ПКМ по сравнению с исходным ПТФЭ.В данной работе представлены результаты исследований влияния органомодифицированного механоактивированного монтмориллонита (оММТ) марки 101/102 на физико-механические характеристики и структуру политетрафторэтилена. Содержание наполнителя варьировали от 0,5 до 7 мас. %. Установлено, что при введении 0,1-5,0 мас. % оММТ в ПТФЭ прочность ПКМ увеличивается на 25 %, относительное удлинение на 21%. Структурными исследованиями зарегистрирована трансформация надмолекулярной структуры ПТФЭ с формированием сферолитоподобных образований, центрами кристаллизации которых являются частицы оММТ. Для этих концентраций наполнителя установлены более высокие показатели энтальпии плавления и степени кристалличности методом дифференциальной сканирующей калориметрии. The development of modern technology requires the search for new structural materials that surpass traditional ones in their deformation-strength, elastic and wear-resistant properties. Composite materials based on PTFE are very promising structural materials for many industries.PTFE is widely used in friction units of technical systems due to its operability in a wide temperature range while maintaining low and stable values of the coefficient of friction, as well as its ability to provide self-lubrication during friction. Such disadvantages of PTFE as cold flow, low wear resistance, high coefficient of thermal expansion are eliminated by modification, one of the common methods of which is filling.The paper focuses on the effect of organomodified mechanically activated montmorillonite (OMMT) of 101/102 grade on the physical and mechanical characteristics and structure of polytetrafluoroethylene. The filler content varied from 0.5 to 7 wt. %. With the introduction of 0.1-5.0 wt. % OMMT in PTFE, the strength of PCM increases by 35%, and the elongation by 21% was found. Structural studies have registered the transformation of the supramolecular structure of PTFE with the formation of spherulite-like formations, the centers of crystallization of which are particles of OMMT. For these filler concentrations, higher values ​​of the enthalpy of melting and the degree of crystallinity were established by the method of differential scanning calorimetry.