Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: Vicker’s method

Sortuj według:

Ogranicz wyniki do:

Diamond composites with nanoceramic boride bonding phases

Szutkowska M., Jaworska L., Rozums M., Klimczyk P., Bucko M.

Archives of Materials Science and Engineering

2012

Vol. 53, nr 2

85-91

Purpose: Basic mechanical properties of the studied tool composites and microstructure of diamond- titanium diboride composite, and diamond-titanium diboride-titanium nitride composite with participation of nanopowders have been presented. Design/methodology/approach: Composites were prepared on the basis diamond powders of 3-6 Μ (MDA36, Element Six) and the TiB2/TiN nanopowders of below 45 nm (Neomat Co. Lithuania firm) and nanopowder of TiB2 with size of crystallite below of 100 nm (American Elements firm). Different amount of a bonding phase changing in range from 10 to 30 wt% was used. Compacts in the shape of disc with dimension ∅15x5 mm were sintered at pressure 8.0�}0.2 GPa and temperature of 2235 K using the Bridgman type apparatus. Microstructure studies using scanning microscope, X-ray and electron diffraction phase analysis were used. Findings: The influence of the bonding phase amount on the tested properties was observed. Vicker�fs hardness HV1 was changed in the range from 20.0 to 50.0 GPa, Young�fs modulus (E) from 360 to 600 GPa and density (�Ď) from 3.30 to 3.63 g/cm3. The highest values of Vickers hardness and Young�fs modulus were obtained for diamond composites sintered with 10 wt% TiB2 of bonding phase. Practical implications: In this work the effect of reduction powder size from submicron scale to nano scale of two ceramic bonding phases: titanium diboride and titanium diboride-nitride in diamond composites on selected mechanical properties has been reported. The results show that using of the TiB2 powders in nano scale size increase the Vicker�fs hardness about 30 wt% in comparison to using of the TiB2/TiN phase. Originality/value: These investigations allow enhance possibility of using this materials as burnishing tools and rational use of existing ceramic tools.

Zastosowanie prawa Meyera w badaniach mikrotwardości nasion fasoli

Frączek J., Hebda T.

Inżynieria Rolnicza

2002

R. 6, nr 6

157--166

Badania przeprowadzono na trzech odmianach fasoli: Tara, Jubilatka, Augustynka. Mikrotwardość określono wykorzystując zmodyfikowaną metodę Rockwella. Pomiary zostały wykonane przy sześciu wartościach siły nacisku (0,1; 0,2; 0,5; 1; 1,5; 2 N) dla sześciu poziomów zawartości wody w badanym materiale (0,11; 0,15; 0,19; 0,23; 0,33; 0,42 kg/kg s.m.). Analiza wyników wykazała istotny wpływ wartości siły obciążenia penetratora na twardość pojedynczych nasion. Stwierdzono, że w przypadku badania nasion fasoli prawo Meyera znajduje ograniczone zastosowanie. Uzyskane wyniki przedstawiono na wykresach.

An attempt was made to apply the Meyer’s law in testing of the bean seeds for hardness. The tests were carried out on three bean cultivars: Tara, Jubilatka, Augustynka. The microhardness was determined with the use of modified Rockwell's method. The measurements were taken at six values of loading force (0,1; 0,2; 0,5; 1,0; 1,5; 2,0 N) and six seed moisture contents ( dry basis) ranging from 0,11 to 0,42 kg H2O/kg DM. Analysis of the results showed a significant influence of the force loading penetrator on the hardness of single seeds. It was found that in case of testing the bean seeds the application of Meyer’s law is bounded. Obtained results were presented in the from of diagrams.