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The aim of this study was to obtain ceramic alumina materials by using the conventional free sintering process, 2.45 GHz microwave sintering and spark plasma sintering (SPS). Technical produced by Alcoa and ultra-pure alumina produced by Atlantic Equipment Engineers was used to obtain specimens. After sintering, the materials were subjected to studies of their physical and mechanical properties and carried out SEM observation using scanning electron microscope. The effect of temperature and time of sintering on the density, Young's modulus and Vickers hardness of Al 2 O 3 ceramics was determined. Mechanical and physical properties of the obtained materials were compared between the methods of sintering. On the basis of images from scanning electron microscope was performed quantitative analysis allows to determine the degree of grain growth of alumina after sintering. Our calculations were based on classic formulas of stereology for single-phase structure. The use of advanced sintering processes allowed to receive alumina ceramic materials with good mechanical and physical properties at the time of one minute for microwave sintering to ten minutes for spark plasma sintering. The non-conventional methods for sintering ceramics primarily comprises spark plasma sintering and microwave sintering. Microwave and SPS sintering methods did not prevent grains growth of Al 2 O 3 , and even resulted in their growth. Keywords: ceramic alumina materials, non-conventional sintering methods, grain growth, microstructure investigations Streszczenie: Celem przeprowadzonych badań było otrzymanie spieków tlenku glinu przez zastosowanie konwencjonalnego spiekania swobodnego, mikrofalowego przy częstotliwości mikrofal 2,45 GHz oraz spiekania metodą SPS. Do otrzymywania spieków zastosowano techniczny proszek Al 2 O 3 produkowany przez Alcoa oraz ultraczysty proszek produkowany przez Atlantic Equipment Engineers. Otrzymane spieki były przygotowywane do badań właściwości fizyko-mechanicznych oraz przeprowadzenia obserwacji mikrostrukturalnych przy zastosowaniu skaningowej mikroskopii elektronowej. Określono wpływ temperatury INNOVATIVE MANUFACTURING TECHNOLOGY 2014 250 i czasu spiekania na gęstość, moduł Younga oraz twardość Vickersa ceramiki Al 2 O 3 . Właściwości fizyko-mechaniczne otrzymanych spieków zostały porównane pomiędzy zastosowanymi metodami spiekania. Na podstawie obserwacji SEM wykonano ilościowe analizy i obliczenia pozwalające na określenie stopnia rozrostu ziaren tlenku glinu po spiekaniu. Nasze obliczenia były oparte na klasycznych wzorach stereologicznych dla monofazowej struktury. Zastosowanie zaawansowanych procesów spiekania pozwoliło otrzymać spieki tlenku glinu o dobrych właściwościach fizyko-mechanicznych podczas jednej minuty spiekania mikrofalowego i dziesięciu minut dla spiekania SPS. Niekonwencjonalne metody spiekania obejmują głównie metodę SPS oraz metodę mikrofalową. Metody spiekania mikrofalowego oraz SPS nie zapobiegły rozrostowi ziaren Al 2 O 3 , a wręcz przeciwnie wpłynęły na ich rozrost....

Working parts of slide burnishing tools were made from two new diamond composites with ceramic bonding: MAX Ti3GeC2 and TiB2nano phases, respectively. Microstructure and micro composition were analyzed by scanning and transmission electron microscopy and X-ray diffraction. Vickers hardness HV1 values were 36 and 46 GPa, Young’s moduli 490 and 560 GPa, tensile strengths 400 and 560 MPa, fracture toughness 8.4 and 11.0 MPa·m1/2 and friction coefficient values 0.63 and 0.56, respectively for the composites with MAX Ti3GeC2 and TiB2nano phases. The tools were tested by slide burnishing on previously turned AISI 4140 alloy steel bar. Improvement in the surface geometric structure was demonstrated for both materials, more so in the case of TiB2nano phase, as compared to burnishing bycomposites with MAX Ti3GeC2 phase.

Abstract. High hardness, good thermal and electrical conductivities make titanium nitride technologically important material. The high melting point and low self-diffusion coefficient make it difficult to obtain fully dense material. In this paper the results of Spark Plasma Sintering (SPS) of TiN from micropowders, TiN from nanopowders and TiN micro with 10 wt.% of nano TiN are presented. Morphology and phase composition of starting powders was analyzed. The powders were uniaxially pressed at 35 MPa for 5 minutes. Sintering temperature was in the range from 1200°C up to 2200°C. Relative density ranged from 88%-97% for samples from micropowders and 81%-87% for nanopowder samples. The highest relative density (99%) was achieved for samples with addition of nanopowders. The addition of 10 wt.% TiN nanopowders allows to improve properties of obtained TiN materials and decreased temperature of sintering.