Wyniki wyszukiwania - BazTech

1

Effect of Heat Treatment on Abrasion Wear Resistance of Steel with Micro-Additives of Boron and Vanadium

Białobrzeska Beata, Konat Łukasz

Tribologia

|

2024

|

nr 1

7--19

EN

This paper presents the results of own research regarding the role of microstructure and mechanical properties in the abrasive wear of metallic materials, demonstrated on the example of low-alloyed steel with microadditives of boron and vanadium. The first section discusses the current knowledge relating to the influence of microstructure and hardness on tribological conditions of materials. Further sections present the results of microstructure observations performed with light microscopy as well as with scanning electron microscopy and transmission electron microscopy. This research has focused on the material both in the as-delivered condition (directly after casting) and after heat treatment, which involved quenching and tempering at three temperatures: 200, 400, and 600°C. The tribological tests were performed with the use of the T-07 tribometer, in the presence of loose #90 electro corundum abrasive particles. The test results have been discussed and an attempt has been made to correlate them with the microstructure and selected mechanical properties. In order to identify wear mechanisms, the surfaces were visually inspected after the abrasion process. The inspection results indicate that the main wear mechanisms were microcutting and microploughing.

PL

W pracy zreferowano wyniki badań własnych w zakresie roli mikrostruktury i właściwości mechanicznych w zużywaniu ściernym materiałów metalicznych na przykładzie niskostopowego staliwa z mikrododatkami boru i wanadu. W początkowej części omówiono stan wiedzy dotyczący wpływu mikrostruktury i twardości na właściwości tribologiczne materiałów. Następnie przedstawiono wyniki obserwacji mikrostrukturalnych przeprowadzonych za pomocą mikroskopii świetlnej oraz elektronowej mikroskopii skaningowej. W referowanych badaniach skupiono się na materiale w stanie dostarczenia (bezpośrednio po odlewaniu) oraz na stanie obrobionym cieplnie, obejmującym hartowanie i odpuszczanie w trzech temperaturach, tj. 200, 400 i 600°C. Badania tribologiczne zostały przeprowadzone za pomocą testera T-07 w obecności luźnego ścierniwa, które stanowił elektrokorund #90. Wyniki badań zostały dodatkowe poszerzone o dyskusję oraz próbę ich korelacji z mikrostrukturą i wybranymi własnościami mechanicznymi. W celu ustalenia mechanizmów zużywania, dokonano obserwacji powierzchni po ścieraniu. Na tej podstawie stwierdzono, że głównymi mechanizmami zużycia były mikroskrawanie i mikrobruzdowanie.

2

Investigation of Multi-Cold Rolling Passes on Mechanical Characteristics and Surface Quality of AlCuV Alloy

Shaban Nabeel Abu, Al-Qawabah Safwan, Alkhaldi Hashem S.

Advances in Science and Technology. Research Journal

|

2023

|

Vol. 17, no 5

68--76

EN

In this study, the effect of rolling angle orientation namely; 0, 45, and 90 degrees, and three rolling passes on the mechanical behavior of Al-Cu after vanadium addition were investigated. Al-4%Cu and Al-4%Cu-0.1%V sheets were produced and rolled from 4 mm to 3 mm followed by 3 to 2 mm, and finally from 2 mm to 1.3 mm. After each pass, the tensile test was performed in three directions from which the maximum tensile force, deformation energy, microhardness, and average surface roughness (Ra) were determined. A pronounce finding is that the addition of both additions of 0.1% vanadium to Al-4%Cu alloy and multi-rolling passes resulted in reducing the deformation energy by 85.4, and the maximum tensile forces reduced by 56.6%, this resulted in reduction of production cost of AlCuV alloys, furthermore, it resulted in reducing the anisotropy of AlCuV alloy. Additionally, the average microhardness was enhanced for Al-Cu and AlCuV alloy, whereas the Ra was in maximum enhanced for AlCuV alloy of about 64.9%.

3

Hydrogen Dilatation of V-Based Composite Membranes

Panichkin Alexander, Mamaeva Axaule, Kenzhegulov Aidar, Karboz Zhanar

Archives of Metallurgy and Materials

|

2022

|

Vol. 67, iss. 2

767--772

EN

One of the problems limiting the use of vanadium as hydrogen permeable membranes is its high dilatation upon hydrogen dissolution in it. The information available for the dilatation coefficient value (Δυ/Ω) is contradictory, experimental information on the hydrogen solubility in vanadium within 100-1000 kPa at from 250 to 700°С is very limited. It does not enable to calculate the membrane dilatation. The article contains the measuring results for dilatation of strips made of vanadium foil 100 μm thick in a hydrogen atmosphere in the pressure range from 75 to 1000 kPa, temperatures from 250 to 700°С. The dilatation coefficient (Δυ/Ω) of polycrystalline vanadium was calculated based on the data obtained for dilatation and data previously published for the hydrogen concentration in the α-solid solution at 400°С. It is 0.165. Isobars for the temperature dependence of the hydrogen concentration in vanadium are calculated and constructed using the dilatation measuring results and the dilatation coefficient values. These data are agreed with theoretical and experimental data published previously. The limiting change in concentration and linear dimensions over the cross section of a hydrogen-permeable membrane from V was estimated at various temperatures and operating pressures at the membrane outlet based on the isobars plotted for temperature dependences of the CH/V. The conclusions are made on the optimal working conditions of Pd/V/Pd membranes when hydrogen is released from hydrogen-containing gas mixtures in accordance with Fick’s 1st law and data published previously for hydrogen concentration value at which solid hydrogen solutions in vanadium become brittle.

4

Polimery koordynacyjne wanadu : stan obecny i perspektywy

Augustyniak Adam W.

Wiadomości Chemiczne

|

2021

|

[Z] 75, 3-4

253--269

EN

Vanadium ions are very attractive building units owing to their coordination diversity. In recent years, metal-organic polyhedra (MOP) and metal-organic frameworks (MOFs) have gradually become attractive materials in various fields due to their unique properties. However, despite this, structures based on vanadium ions are scarce. This short perspective review paper describes representative examples of MOP and MOFs based vanadium, focusing on their structure and their applications.

5

Związki kompleksowe chromu(III), wanadu(IV) i kobaltu(II) jako nowe prekatalizatory polimeryzacji olefin

Drzeżdżon Joanna

Wiadomości Chemiczne

|

2020

|

[Z] 74, 5-6

423--437

EN

The olefin polymerization catalysts constitute a large group of various compounds. Metallocene complexes are the largest part of this group. However, due to the instability at industrial plastics temperatures and the decomposition of complexes after MAO (or MMAO) activation, they have been partly replaced by non-metallocene compounds. This article concerns the studies on new non- metallocene precatalysts for the olefin polymerization and oligomerization. The report focuses on the structure and the catalytic activities of the complexes of chromium(III), vanadium(IV) and cobalt(II) with the following ligands: dipicolinate, 2-pyridinecarboxylate, oxalate, oxydiacetate, iminodiacetate, 2,2’- bipyridine, 4,4’-dimethoxy-2,2’-bipyridine, 1,10-phenantroline. These complex compounds are highly active precatalysts for olefin polymerization and oligomerization. The complexes: [Cr(dipic)2][Cr(bipy)(dipic)H20] 2H20 and [Cr(dipic) 2]Hdmbipy 2.5H20 deserve special attention because they are new type of the precatalysts i.e. organic salt type complexes composed both of organic cations and anions. These compounds are not only interesting because of their structure but also because of their high catalytic activity.

6

Separation and Immobilization of Vanadium from Industrial Fly Ash as an Insoluble Inorganic Pigmen

Kwolek P., Czubajewski K., Wojnicki M.

Archives of Metallurgy and Materials

|

2020

|

Vol. 65, iss. 2

901--909

EN

It has been shown that the precipitation of bismuth orthovanadate from a fly ash leachate is a promising method of vanadium recovery. BiVO4 obtained after appropriate heat treatment can be sold as a pigment. The yield of recovery of solubilised vanadium is equal to 68% and the precipitate is free from nickel impurity. The precipitate is insoluble in the solutions with pH ≥ 3. In more acidic media the solubility of precipitate increases with the decreasing pH. The solubility of the precipitate increases also with the increasing concentration of chloride ions.

7

Effects of Adding Niobium and Vanadium to Fe-Based Oxide Dispersion Strengthened Alloy

Park Chun Woong, Choi Won June, Byun Jong Min, Kim Young Do

Archives of Metallurgy and Materials

|

2020

|

Vol. 65, iss. 4

1265--1268

EN

In this study, the effects of adding niobium and vanadium to Fe-based oxide dispersion strengthened alloys are confirmed. The composition of alloys are Fe-20Cr-1Al-0.5Ti-0.5Y2 O3 and Fe-20Cr-1Al-0.5Ti-0.3V-0.2Nb-0.5Y2 O3. The alloy powders are manufactured by using a planetary mill, and these powders are molded by using a magnetic pulsed compaction. Thereafter, the powders are sintered in a tube furnace to obtain sintered specimens. The added elements exist in the form of a solid solution in the Fe matrix and suppress the grain growth. These results are confirmed via X-ray diffraction and scanning electron microscopy analyses of the phase and microstructure of alloys. In addition, it was confirmed that the addition of elements, improved the hardness property of Fe-based oxide dispersion strengthened alloys.

8

Tridentate hydrazido-hydrazones vanadium complexes. Synthesis, properties and biological activity

Szklarzewicz Janusz, Jurowska Anna, Hodorowicz Maciej, Matoga Dariusz, Gryboś Ryszard, Filipek Barbara, Sapa Jacek, Głuch-Lutwin Monika, Mordyl Barbara, Kazek Grzegorz

Science, Technology and Innovation

|

2019

|

Vol. 4, no. 1

9--20

EN

Nine new vanadium complexes, with tridentate Schiff base ligand based on 3,5-di-tertbutyl-2-hydroxybenzaldehyde and different hydrazides, are described and characterized. The X-ray crystal structure of complex 8 shows distorted octahedral geometry of vanadium, with ONO ligand in equatorial position. The tridentate Schiff base ligand forms six membered and five-membered chelate rings at the V(V) acceptor center, with the corresponding bite angles being 82.97(9)˚ and 74.48(9)˚. The molecules are gathered by means of intermolecular OH...N hydrogen bond and layered by π...π interactions involving the pyridine and phenolate rings. Such interactions expand the structure along the crystallographic a axis. The complexes were characterized by the elemental analyses, IR, UV-Vis, EPR spectroscopy, cyclic voltammetry, thermogravimetry and magnetic susceptibility measurements. The stabilization role of co-ligands is discussed. The cytotoxicity versus HepG2 hepatocytes and inhibition of human recombinant PTP1B was studied.

9

Thermal and long period stability of series of V(V), V(IV) and V(III) complex with Schiff base ligands in solid state

Szklarzewicz Janusz, Jurowska Anna, Hodorowicz Maciej, Gryboś Ryszard

Science, Technology and Innovation

|

2019

|

Vol. 4, no. 1

30--36

EN

The synthesis and physicochemical properties of three new complexes of vanadium at +5, +4 and +3 oxidation state are described and discussed. The octahedral surrounding of vanadium for V(III) complexes of [V(L1)(HL1)] general formula is filled with two ONO tridentate ligand L, for V(IV) one ONO ligand L, oxido ligand and 1,10-phenanthroline (phen) as a co-ligand are presented in complexes of [VO(L2)(phen)]. For V(V) the complexes of [VO2(L1)(solv)] type were formed. As ligands, the H2L Schiff bases were formed in reaction between 5-hydroxysalcylaldehyde and phenylacetic hydrazide (H2L1) and 3,5- dichlorosalicyaldehyde and 4-hydroxybenzhydrazide (L2). The magnetic moment measurements, in 8 year period, show, that V(III) complexes slowly oxidise to V(IV) with preservation of the nonoxido character of the complexes, while V(IV) complexes were found to be stable. The TG and SDTA measurements indicate, that thermal stability depends mainly on the oxidation state of vanadium. The less thermally stable are the V(V) complexes, while V(IV) and V(III) are stable up to ca. 200oC. In solution, at pH 2 (similar to that in human digestion system), again the V(IV) are the most stable, only at pH 7.0 V(III) complexes had higher stability. The most stable, thus best for pharmaceutical use, are V(IV) complexes.

10

The influence of chronic supply of vanadium compounds on organ weights and body mass in animal diabetes model (NZO)

Krośniak Mirosław, Szklarzewicz Janusz, Gryboś Ryszard, Tatar Barbara, Yildirim Metin, Sahin Bilge, Yuksek Nafize Didem, Ustundag Mustafa

Science, Technology and Innovation

|

2019

|

Vol. 4, no. 1

63--73

EN

Vanadium is an element that has an effect on improving glucose levels in animals with diabetes. However, its operation is strongly dependent on the chemical structure of compounds of this element. The influence of newly synthesized vanadium compounds on biochemical processes is also unknown. The paper presents the influence of eight new vanadium compounds on organ weights of animals (mice NZO) in whom diabetes was induced by a high-fat diet during 8 weeks. Tested vanadium complexes were administered by 5 weeks. After this time organs were collected and weighed. Tested complexes had a remarkable different effect on organ weights, despite having similar composition ([VO(L)(phen)] and the same co-ligand (1,10-phenanthroline) . This indicate on separate metabolic pathways of these compounds in the body of tested animals and role of the tridentate L Schiff base ligands. The compounds C2, C3 and C5 shoved biggest influence on organs weight and these results suggest influence on the metabolic pathways and therefore are interesting for further investigations.

11

Synthesis, structure and properties of V(V) monooxido complex with ONO tridentate Schiff base

Jurowska Anna, Szklarzewicz Janusz, Hodorowicz Maciej, Gryboś Ryszard

Science, Technology and Innovation

|

2019

|

Vol. 4, no. 1

21--29

EN

The oxidovanadium(V) Schiff base complex of formula [VO(L)(EtO)(EtOH)] (where H2L = Schiff base ligand derived from 5-methoxysalicylaldehyde and phenylacetic hydrazide) was synthesized and described. Complex crystalizes in triclinic P-1 space group. Octahedral geometry of the vanadium(V) centre is filed with oxido, ONO L2- ligand and two solvent molecules both in ethoxo and as neutral ethanol form. The complex is neutral, with 5- and 6-memebered ring formed by ONO ligand coordinated in octahedral plane with oxido and EtOH ligands in vertical positions. Two isomers are present in the unit cell, with different position of 5-membered ring versus vertical plane. The elemental analysis, magnetic susceptibility, thermogravimetry and spectroscopy (IR, UV-Vis) measurements were measured and are discussed. The cyclic voltammetry measurements show irreversible processes for vanadium(IV/V) redox system. Thermal stability both in a solid state (TG and SDTA measurements) as well as in solutions (at pH 7.0 and 2.0, studied by UV-Vis spectroscopy) is discussed.

12

Synthesis, structure and properties of V(IV) complex with N’-[(E)-(2,3-dihydroxyphenyl)metylidene]-2- phenylacetohydrazide

Szklarzewicz Janusz, Jurowska Anna, Hodorowicz Maciej, Gryboś Ryszard

Science, Technology and Innovation

|

2019

|

Vol. 4, no. 1

1--8

EN

The synthesis and physicochemical properties of new vanadium(IV) complex of formula [VO(L)(phen)] is described. The L denotes ONO tridentate Schiff base derived from 2,3-dihydroxybenzaldehyde and phenylacetic hydrazide, while phen = 1,10-phenanthroline used as a co-ligand to stabilize the V(IV) oxidation state. The single crystal X-Ray crystal structure indicates on octahedral geometry of vanadium centre, with 1,10-phenanthroline nitrogen trans to the V=O bond. The complex crystalizes in a monoclinic P21/c space group, very unusual is that only one isomer is present in the crystal structure. The structure is stabilized by very weak hydrogen bonds and H··π and π···π interactions. The phenyl ring of hydrazide is strongly curved from ONO ligand plane by 70.95˚. The spectroscopic characterization (IR, UV-Vis) as well as the cyclic voltammetry measurements are presented and discussed

13

Synthesis, structure and properties of V(III, IV and V) complexes with ONO Schiff bases

Szklarzewicz Janusz, Jurowska Anna, Olszewska Agata, Hodorowicz Maciej, Gryboś Ryszard, Kruczała Krzysztof

Science, Technology and Innovation

|

2019

|

Vol. 4, no. 1

37--46

EN

The synthesis and physicochemical properties of vanadium(III,IV,V) complexes with Schiff base ligands based on 3,5-dibromo-4-methoxy-salicylaldehyde and phenylacetic hydrazide (H2L1), 5-chlorosalicylaldehyde and 4-hydroxybenzhydrazide (H2L2) and 5- chlorosalicylaldehyde and 2-hydroxybenzhydrazide (H2L3) were presented. The formulas of the complexes {[V(L1)(HL2)]·EtOH (1), [VO(L2)(phen)]·2H2O (2) and [VO(L3)(EtO)] (3)} were proposed based on the elemental analysis, IR and UV-Vis spectra. Additionally, the IR and UV-Vis spectra (in solvents as well as in a solid state) have been discussed from the vanadium oxidation state point of view. The single crystal structure of 3 shows triclinic, P-1 space group, structure is stabilized by hydrogen bonds and strong π-π stacking interactions. The oxidation state of the metal centre was also confirmed by the magnetic susceptibility measurements. The stability of the complexes was measured in pH = 7.00 and in pH = 2.00 which allows to evaluate the use of these compounds as insulin mimetic compounds.

14

Odzysk wanadu z odpadów przemysłowych - przegląd literatury

Wojnicki Marek, Czubajewski Karol, Kwolek Przemysław

Rudy i Metale Nieżelazne Recykling

|

2019

|

R. 64, nr 6

17--20

PL

Wanad należy do grupy metali nieżelaznych, stanowiący jeden z podstawowych dodatków do stopów z przeznaczeniem na narzędzia. Obecność wanadu w stopach, znacząco poprawia właściwości mechaniczne. Niestety jego wysoka cena powoduje, iż na rynku pojawiają się fałszywe stopy, które rzekomo mają posiadać wanad lub jego zawartość jest zaniżona względem optymalnych parametrów. Ze względu na jego wysoką cenę, ograniczone źródła naturalne oraz jego toksyczność, koniecznym jest rozsądne i przemyślane zarządzanie zasobami, oraz odpadami zawierającymi ten metal oraz jego sole. W pracy przedstawiono przegląd literatury na temat recyklingu wanadu i jego źródeł antropogenicznych.

EN

Vanadium belongs to the group of non-ferrous metals, which is one of the basic additions to alloys for tools. The presence of vanadium in the alloys, significantly improves mechanical properties. Unfortunately, its high price results in the appearance of false of alloys on the market that allegedly have vanadium. Due to its high price, limited natural sources and its toxicity, it is necessary to have a reasonable and well thought-out management of resources and waste containing this metal and its salts. The following paper presents an overview of the literature on vanadium recycling from its anthropogenic sources.

15

Identyfikacja domieszek V, Co, Ni i Au w minerałach kruszcowych rud Fe-Ti-V (NE Polska) na podstawie analiz mikrosondą rentgenowską (EMPA)

Sadłowska Katarzyna, Mikulski Stanisław Z.

Przegląd Geologiczny

|

2019

|

Vol. 67, nr 3

192--195

EN

The main objective of this study was to quantitatively and qualitatively idenify trace metal admixtures in ore mineralsfrom Fe-Ti-V ore deposits within the Suwałki Anorthosite Massifin NE Poland. Chemical composition of ore minerals was determined using the CAMECA SX-100 electron microprobe and scanning electron microscope. The most abundant trace elements were Ti and Vhosted in oxides and Co, Ni, Cu, Zn contained in sulphides such aspentlandite, pyrrhotite, chalcopyrite, pyrite, siegenite, millerite. Scarce occurrences of native Bi, hessite and greenockite were identified. Samples, which were depleted in iron oxides were enriched in REE due to the presence of zircon, apatite and monazite.

16

Czynniki decydujące o wpływie metali ciężkich na wiązanie cementu portlandzkiego

Pichniarczyk Paweł

Cement Wapno Beton

|

2019

|

R. 24/86, nr 6

455--461

PL

Wykazano doświadczalnie jakie są główne czynniki decydujące o wpływie dwóch tlenków metali ciężkich: ołowiu oraz wanadu na wiązanie cementu portlandzkiego. Głównymi czynnikami decydującymi o wpływie tych metali są: a) stężenie jonów siarczanowych w fazie ciekłej zaczynu cementowego, b) szybkość rozpuszczania się metali ciężkich w fazie ciekłej zaczynu, c) postać w jakiej dodawane są metale ciężkie w przypadku występowania różnicy w szybkości rozpuszczania metalu i jego tlenku. Gdy stężenie jonów siarczanowych jest małe w pierwszych 20 minutach od dodania wody, szybko rozpuszczający się ołów hamuje tworzenie się warstewki ettringitu na ziarnach C3A, co powoduje szybkie wiązanie „ettringitowe”. W przypadku małej szybkości rozpuszczania metali i ich niewielkiego stężenia w roztworze, warstewka ettringitu tworzy się na kryształach C3A i metale te nie mają praktycznie żadnego wpływu na początek wiązania. Tak jest w przypadku wanadu, natomiast ma on opóźniający wpływ na koniec wiązania.

EN

It was proved experimentally in the work what are the main factors governing the influence of two heavy metals: lead and vanadium on the setting of Portland cement. The main factors governing the behaviour of these metals are as follows: a) concentration of sulphate ions in the cement paste liquid phase, b) the rate of dissolution of heavy metals in this liquid phase, c) the form of heavy metals addition, in the case when there is a high difference in the rate of dissolution between metal and its oxide. When the concentration of sulphate is low in the first 20 minutes after addition of mixing water the quick dissolution lead is preventing the formation of ettringite layer on C3A and the quick “ettringite” setting takes place. When the metals have low dissolution rate and low concentration in solution the ettringite layer is formed on C3A crystals and these metals have practically no influence on the initial setting time. There is the case of vanadium, but it has retarding effect on the final setting time of cement.

17

Method of utilization of the spent vanadium catalyst

Mazurek K., Grzesiak P., Drużyński S., Kiełkowska U., Wróbel A., Szalla A.

Polish Journal of Chemical Technology

|

2018

|

Vol. 20, nr 3

1--7

EN

A spent vanadium catalyst, from the plant of metallurgical type, was leached in a potassium hydroxide solution to recover vanadium. The effect of time, temperature, concentration of basic, catalyst particle size and phase ratio was studied. The results showed that for a 160–750 μm catalyst leached for 4 h at 313.15 K in the presence of 10% potassium hydroxide solution at a liquid: solid ratio of 20:1, the extent of leaching of V was about 87%. Additionally, separation of vanadium from such a solution was investigated by the ion exchange method. Two types of polymer strongly basic ion exchangers were used. The ion exchange tests indicate that vanadium were loaded from the post-leaching solution with high efficiency. On this basis a flowsheet for the proposed process of a complex utilization of the spent vanadium catalyst is presented.

18

A novel method to extract vanadium from vanadium-bearing steel slag using sodium carbonate solution

Gao M., Xue X., Li L., Yang H., Bai R., Wang H.

Physicochemical Problems of Mineral Processing

|

2018

|

Vol. 54, iss. 3

911--921

EN

A new method using sodium carbonate solution to treat a vanadium-bearing steel slag is proposed. The effects of the particle size, solid-to-liquid ratio, initial concentration of sodium carbonate solution, leaching temperature and stirring speed on the leaching rate of vanadium were investigated. The leaching kinetics of vanadium from the vanadium-bearing steel slag was studied, which indicated that the leaching rate was controlled by the step of diffusion through the solid layer around the unreacted core. The apparent activation energy for the process was 13.75 kJ/mol. By using this process, vanadium could be extracted effectively with the leaching rate of more than 80%.

19

Structural analysis of iron based intermetallic phases in secondary AlSi6Cu4 cast alloy

Svecova I., Tillova E., Kucharikova L.

Production Engineering Archives

|

2017

|

Vol. 15

3--6

EN

The use of secondary aluminum alloys is increasing because it contributes to the decrease of production costs. However, these alloys contain bigger amount of iron. Iron has a negative effect and therefore its elimination is necessary in order to add some elements, which are also called correctors of iron. The most frequently used corrector is manganese. Another quite often used correctors are chromium, potassium, magnesium, vanadium. In the following work, vanadium is used as a corrector of iron phases. The application of vanadium in aluminum alloys has a positive impact on their mechanical properties, increases the tensile strength, ductility and hardness. As experimental material AlSi6Cu4 alloy was used. It was alloyed by master alloy AlFe10. After adding to the master alloy the iron content, the critical value in the alloy exceeded. Vanadium was added to AlSi6Cu4 alloy in different quantities. The image analysis (software NIS-Elements) was used for quantifying the amount of iron based intermetallic phases and determination of average values.

20

Wpływ wanadu na proces krystalizacji, mikrostrukturę i właściwości siluminu EN AC-46000

Szymczak T., Gumienny G., Pacyniak T.

Prace Instytutu Odlewnictwa

|

2017

|

Vol. 57, no. 3

187--199

PL

W niniejszej pracy przedstawiono wyniki badań siluminu z dodatkiem wanadu przeznaczonego do odlewania pod ciśnieniem. Jako stop wyjściowy zastosowano silumin podeutektyczny gatunku EN AC-46000. Do siluminu wyjściowego wprowadzano zaprawę AlV10 w ilości pozwalającej na uzyskanie zawartości wanadu w kolejno wytapianych siluminach po około 0,1; 0,2; 0,3; 0,4 i 0,5% wag. Badaniom poddano zarówno silumin wyjściowy, jak i siluminy zawierające wanad. Badania obejmowały analizę termiczną i derywacyjną (ATD) procesu krystalizacji, analizę metalograficzną mikrostruktury odlewów wykonanych w próbniku ATD i ciśnieniowych oraz określenie podstawowych właściwości mechanicznych siluminu odlewanego ciśnieniowo. Badania ATD wykazały wzrost temperatury początku krystalizacji siluminu oraz brak dodatkowych efektów cieplnych. Badania metalograficzne wykazały zmniejszenie średniej wielkości faz w mikrostrukturze stopu odlewanego do próbnika ATD. W siluminach zawierających 0,3; 0,4 i 0,5% wag. V zarówno płytkowe wydzielenia krzemu eutektycznego, jak i faz międzymetalicznych pochodzących z eutektyk charakteryzują się znacząco mniejszymi maksymalnymi wymiarami w porównaniu z siluminami o mniejszej zawartości V. W mikrostrukturze siluminów odlewanych pod ciśnieniem, które zawierają wanad powstają „nowe” fazy niewystępujące w siluminach niezawierających tego pierwiastka. Są to najprawdopodobniej fazy międzymetaliczne zawierające wanad. Wielkość wydzieleń tych faz rośnie wraz ze zwiększeniem zawartości wanadu w siluminie. Przeprowadzone badania podstawowych właściwości mechanicznych siluminów odlewanych pod ciśnieniem wykazały możliwość uzyskania większych wartości wytrzymałości na rozciąganie Rm, umownej granicy plastyczności Rp0,2 oraz twardości HB siluminów zawierających wanad w porównaniu z siluminami bez tego pierwiastka. Największe wartości: Rm = 248 MPa uzyskano w siluminie zawierającym około 0,3% wanadu; Rp0,2 = 113 MPa przy zawartości 0,1 i 0,2% oraz HB = 116 dla dodatku V około 0,2% wag. Względem siluminu bez dodatku V uzyskane wartości powodują podwyższenie Rm o 26%; Rp0,2 o 12% oraz HB o 7%.

EN

The paper presents the results of the study of Al-Si alloys with a vanadium addition used in pressure casting. The hypoeutectic Al-Si alloy grade EN AC-46000 was applied as the initial alloy. The master alloy AlV10 was introduced into the initial alloy in the amount making it possible to obtain the vanadium content in the consecutively melted Al-Si alloys of about 0.1; 0.2; 0.3; 0,4 and 0.5 wt. %. The tests were performed on both the initial Al-Si alloy and alloys containing vanadium. The investigations included a thermal and derivative (DTA) analysis of the crystallization process, a metallographic analysis of the microstructure of casts prepared in DTA tester and pressure casts, as well as the determination of the basic mechanical properties of the pressure cast Al-Si alloy. The DTA tests showed an increase in the temperature at the beginning of the Al-Si alloy crystallization and no additional thermal effects. The metallographic examinations demonstrated a decrease of the average phase size in the microstructure of the alloy cast in the DTA tester. In the Al-Si alloys containing 0.3; 0.4 and 0.5 wt. % V, both the lamellar precipitates of eutectic silicon and of the intermetallic phases originating in the eutectics were characterized by significantly lower maximal dimensions, compared to the Al-Si alloys with lower V contents. In the microstructure of the pressure cast Al-Si alloys, which contain vanadium, “new” phases may form, which did not occur in the Al-Si alloys without V. These are probably intermetallic phases containing vanadium. The size of these precipitates increases with the increase of the vanadium content in the Al-Si alloy. The performed tests of the basic mechanical properties of the pressure cast Al-Si alloys showed the possibility of obtaining higher values of tensile strength Rm, proof stress Rp0.2 and hardness HB of the Al-Si alloys containing vanadium, compared to the Al-Si alloys without this element. The highest values: Rm = 248 MPa were obtained in the Al-Si alloy containing about 0.3% vanadium; Rp0.2 = 113 MPa – with the content of 0.1, and 0.2% and HB = 116 for the V addition of about 0.2 wt. %. As regards the Al-Si alloy without a vanadium addition, the obtained values caused an increase of Rm by 26%; Rp0.2 by 12% and HB by 7%.