Green Compact Temperature Evolution during Current-Activated Tip-Based Sintering (CATS) of Nickel

Abstract

Current-activated tip-based sintering (CATS) is a novel process where spark plasma sintering conditions are applied through an electrically conducting tip on a locally controlled area on a green powder compact/bed. The localization of electric current in CATS allows for unique temporal and spatial current and temperature distributions within the tip and powder compact. In this paper, special experimental setups were used to monitor the temperature profiles in the tip and at multiple locations on the surface of nickel powder compacts. A variation in the initial green density was found to have a significant effect on the maximum temperature in the tip as well as the temperature distribution across the powder compact. In general, the lowest green density specimens displayed the best conditions for localized densification. The concept of effective current density is introduced and results are discussed in relation to the densification parameter.

Characteristics of FeCuAl Powder Compacts Formed through Uniaxial Die Compaction Route

“…Generally higher electrical resistivity was measured at the samples sintered for longer time. Theoretically, higher electrical resistivity means lower electrical conductivity means the electrical current cannot flow easily through the samples which is the indication of the existence of micro-racks/interconnected pores inside the sintered samples [11]. Current Trends in Materials Engineering II Bending strength of the samples compacted at different temperatures and sintered for different times is depicted in Fig.…”

Obtaining and properties of rolled products from clad powders NPG-80 and Nibon-20

“…При формовании металлического порошка прокаткой и другими способами формования при воздействии на очаг деформации электрического тока и электромагнитного поля возникают электрофизические эффекты, упрочняющие материал и сам межчастичный контакт [7; 8]. Большую роль играют электрофизические свойства самого материала проводника, электропластичес кий эффект и другие эффекты, на что серьезное внимание обращают зарубежные и отечественные исследователи [9][10][11][12][13][14][15][16].…”

“…С помощью электропрокатки могут быть изготовлены и другие ленточные материалы. Результаты исследований в области электрокомпактирования металлических порошковых материалов показывают упрочнение металлических материалов при воздействии электромагнитного поля [13][14][15][16][17][18][19][20]. Токи высокой плотности применяются в современных технологиях обработки металлических материалов [21][22][23].…”