Wyniki wyszukiwania - BazTech

1

Microstructure Evolution and Mechanical Properties of C-Mn Cold Rolled Dual Phase Steel after Continuous Annealing Process in Laboratory Conditions

Šebek M., Horňak P., Zimovčák P., Longauer S.

Archives of Metallurgy and Materials

|

2014

|

Vol. 59, iss. 2

821--824

EN

The article deals with the influence of annealing parameters on evolution of microstructure and mechanical properties of dual phase steel. Dual phase steel was annealed in laboratory conditions according to the three chosen cycles of annealing: into intercritical region (780°C), into austenite region (920°C) and into austenite region (920°C) by subsequently cooling into intercritical region (780°C) with the hold at the temperature of 495°C. Simulation of annealing regimes by thermo-mechanical simulator Gleeble was done. The obtained microstructure consists from three phases: ferritic matrix, martensite and martensite/ bainite grains. For the microstructure identification the TEM and nanoindentation experiments were performed.

PL

Praca dotyczy wpływu parametrów wyżarzania na zmiany mikrostruktury i właściwości mechaniczne stali dwufazowej C-Mn. Stal dwufazową poddano wyżarzaniu w warunkach laboratoryjnych według trzech wybranych cykli: w zakresie między krytycznym (780°C). w obszarze austenitu (920°C) i w obszarze austenitu (920°C) ze schładzaniem do zakresu międzykrytycznego (780°C) przy temperaturze wytrzymania 495°C. Przeprowadzono symulację schematów wyżarzania przy użyciu symulatora obróbki cieplno-plastycznej Gleeble. Uzyskana mikrostruktura składa się z trzech faz: osnowy terrytycznej. martenzytu oraz ziaren martenzytu/bainitu. W celu identyfikacji mikrostruktury wykonano badania metodą TEM oraz nanoindentacji.

2

Effect of Cu addition on the GFA, structure and properties of Fe-Co-based alloy

Lesz S., Babilas R., Madej M., Nowosielski R.

Archives of Materials Science and Engineering

|

2012

|

Vol. 55, nr 2

70-77

EN

Purpose: The aim of the paper was investigation of the effect of Cu addition on GFA (Glass Forming Ability), structure, magnetic and mechanical properties of amorphous Fe-Co-B-Si-Nb alloy. Design/methodology/approach: The following experimental techniques were used: differential thermal analysis (DTA), transmission electron microscopy (TEM) and X-ray diffraction (XRD) method, measurements of magnetic properties (VSM method), Vickers microhardness (HV). Findings: It was shown that when Cu is added to the Fe-Co-based alloy, increase of the GFA and change of the magnetic properties was obtained. Research limitations/implications: The results can give more details to understand the relationship between structure, magnetic and mechanical properties. Thus can be useful for practical application of these alloys. Practical implications: The (Fe36Co36B19Si5Nb4)100-xCux (x=0 and 0.6) metallic glasses due to their excellent soft magnetic properties have shown great industrial value for commercial application. Many products consisting of these kinds of metallic glasses have been widely used, for example anti-theft labels, precision sensor material, and high efficient magnetic transformers in electronic industry. Originality/value: The applied investigation methods are suitable to determine the changes of GFA and structure combined with magnetic and mechanical properties of (Fe36Co36B19Si5Nb4)100-xCux (x=0 and 0.6) metallic glasses

3

Influence of copper addition on properties of (Fe36Co36B19Si5Nb4)100-xCux metallic glasses

Lesz S., Stokłosa Z., Nowosielski R.

Archives of Materials Science and Engineering

|

2009

|

Vol. 38, nr 1

12-18

EN

Purpose: The main aim of the paper was investigation of influence of copper addition on thermal, magnetic and mechanical (microhardness) properties of (Fe36Co36B19Si5Nb4)100-xCux (x=0 and 0.6) metallic glasses. Design/methodology/approach: The following experimental techniques were used: differential thermal analysis (DTA), transmission electron microscopy (TEM) and X-ray diffraction (XRD) method, measurements of magnetic properties, Vickers microhardness. Findings: It was shown that addition of small amount of copper to the base alloy induced a change of thermal, magnetic and mechanical properties. Research limitations/implications: The relationship between structure and magnetic and mechanical properties can be useful for practical application of these alloys. Practical implications: The (Fe36Co36B19Si5Nb4)100-xCux (x=0 and 0.6) metallic glasses due to a unique properties have been commercialized in the following application fields: precision mould material, precision imprint material, precision sensor material, precision machinery material and surface coating material. Originality/value: The originality of the paper are examinations of changes of thermal and mechanical properties combined with magnetic properties of the (Fe36Co36B19Si5Nb4)100-xCux (x=0 and 0.6) metallic glasses. Keywords: Amorphous materials; Thermal properties; Magnetic properties; Mechanical properties; DTA; XRD; TEM method.

4

Oczyszczanie i nawęglanie nc-TiC/C w argonie. Analiza kinetyczna

Biedunkiewicz A.

Inżynieria Materiałowa

|

2008

|

Vol. 29, nr 6

667-673

PL

Przedstawiono wyniki analizy procesu oczyszczania i nawęglania n-TiC/C w argonie, otrzymanego metodą zol-żel. Cząstki obrazowano metodą TEM. Strukturę i wielkość cząstek określano metodą XRD. Produkty gazowe oznaczano metodą MS. Pomiary TG-DSC przeprowadzono w warunkach nieizotermicznych i izotermicznych. Próbki w seriach ogrzewano do 1200, 1300, 1400 i 1500°C. Odpowiednie nawęglenie i właściwą wielkość cząstek uzyskano w serii do 1300°C. Dla tej serii podano opis kinetyki procesu. Wyróżniono trzy etapy. W etapie pierwszym następowało uwalnianie i desorpcja produktów lotnych . W etapie drugim zachodziło utlenianie nie nawęglonego nc-TiC/C tlenem zawartym w śladowych ilościach w argonie. W etapie trzecim przebiegała piroliza domieszek i nawęglanie nc-TiC/C. Kinetykę opisano stosując równanie Coatsa-Redferna. Zidentyfikowano dla etapów modele kinetyczne (postacie funkcji g(&)) i wyznaczono parametry Arrheniusa. Stosując uzyskane dane kinetyczne przeprowadzono analizę procesu. Badano zależności &(T) i r(&,T) od szybkości ogrzewania próbek i od temperatury.

EN

The analysis results of purification and carbonization process in argon with use of nc-TiC/C powder, obtained by sol-gel method, are presented. The particles have been depicted by TEM method, while characterization of structure and particles size was performed by XRD method. MS method was used to determine evolved gaseous products. TG-DSC measurements were carried out under non-isothermal and isothermal conditions. The samples were heated up in series to 1200, 1300, 1400 and 1500oC. Appropriate carbonization and particles size were obtained for series heated up to 13000C. For this series description of process kinetics is presented. Three stages of the process hale been distinguished. In the first stage evolution and desorption of volatile products took place. In the second stage occurred oxidation of uncarbonized TiC/C by the oxygen present in argon at trace level. In the third stage the pyrolysis of admixtures and carbonization of nc-TiC/C proceeded. Kinetics were described using Coats-Redfern equation. The kinetic models (forms of g(?) function) and Arrhenius parameters were determined for particular stages. Using obtained kinetic data, the analysis of the process was performed. The ?(T) and r(?,T) dependencies on heating rate and temperature were investigated.