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1

Mikrostruktura natapianej powłoki Ni-Cr-B-Si

Kondej A., Babul T.

Przegląd Spawalnictwa

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2016

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R. 88, nr 3

23--26

PL

Stopy Ni-Cr-B-Si są stosowane do lutowania twardego oraz do modyfikacji powierzchni w celu zwiększenia odporności na zużycie ścierne. Lutem twardym z tej grupy jest BNi-2, stosowany do łączenia stali nierdzewnych, żaroodpornych stopów niklu oraz stali stopowych. W pracy lut BNi-2 w postaci folii wykorzystano jako materiał powłokowy. Stop po natopieniu i wygrzaniu w piecu próżniowym tworzy wielofazową powłokę. Celem pracy było opisanie mikrostruktury powłoki. Wyniki badań wskazują na występowanie czterech obszarów o różnej morfologii. Wykazano obecność roztworu stałego na bazie niklu, borków niklu, borków chromu oraz krzemków niklu.

EN

The Ni-Cr-B-Si alloys are used for brazing and for surface modification to increase the wear resistance. The brazing alloy from this group is BNi-2, used for joining stainless steels, heat-resistant nickel alloys and alloy steels. In the work the brazing alloy BNi-2 in foil form was used as a coating material. The alloy after surfacing and soaking in a vacuum furnace forms a multiphase coating. The purpose of this work was to describe the microstructure of the coating. The results indicate on the incidence of four areas of different morphology. The presence of the solid solution based on nickel, nickel borides, chromium borides and nickel silicides was demonstrated.

2

Identification of precipitations in anodically dissolved high-strength microalloyed Weldox steels

Ozgowicz W., Kurc A., Nawrat G.

Archives of Materials Science and Engineering

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2008

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Vol. 31, nr 2

95-100

EN

Purpose: The aim of the investigations is to elaborate the optimum conditions of anodic dissolutions from highstrength microalloyed Weldox steels in order to obtain indispensable quantities of electrolytic extractions and to identify them by X-ray phase analysis. Design/methodology/approach: Anodic dissolution of steel was carried out according to the potentiostatic method. In the X-ray qualitative analysis the comparative method was applied. The corrosion resistance of steels was determined by means of the first method of Stern - Tafel. Findings: The activity of anodic dissolution of the investigated steel was determined in various solutions of electrolytes with different pH and a different complexive affect versus iron. Practical implications: It has been found that the application of an optimal reagent for the anodic dissolution of Weldox Steel and of the chronopotentriometric method permit to get the required mass of electrolytic extraction for the qualitative X-ray phase analysis. Electrochemical investigations permitted also to assess preliminarily the corrosion resistance of the investigated steels. Originality/value: It has been found that there exists a distinct relation between the mass of electrolytic extractions and the kind of the dissolved precipitation and the value of the electrochemical potential of the anodic dissolution of steel, which affects essentially the result of the X-ray phase analysis. Besides, a high corrosion resistance of the investigated steels to the destructive effect of a saline environment and a low resistance to an acid environment have been detected.

3

X-ray diffraction studies of NiTi shape memory alloys

Lekston Z., Łągiewka E.

Archives of Materials Science and Engineering

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2007

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Vol. 28, nr 11

665-672

EN

Purpose: The purpose of this paper is to present the results of the investigations of phase transitions of TiNiCo and Ni-rich NiTi shape memory alloys designed for medical applications. Design/methodology/approach: Temperature X-ray diffraction (TXRD), differential scanning calorimetry (DSC), electrical resistivity (ER) and the temperature shape recovery measurements in three-point bending ASTM 2082-01 tests were used. Findings: It has been found in this work that ageing after solution treatment and annealing below the recrystallization temperature after cold working in the alloys studied create separate reversible B2 ↔ R ↔ B19' transformations. During thermomechanical cycles characteristic temperatures of the reversible B2 ↔ R phase transition remain stable. It was concluded that ageing after solution treatment or recovery during annealing after cold working causes the precipitation process and the changes of the defect structure of the alloys promote transitions with the R-phase contribution. Research limitations/implications: The results of the courses of transformations and their characteristic temperatures obtained by TXRD, DSC and ER techniques have a good correlation. Future TXRD research with the use of automatic rapid recording of diffraction patterns during cooling and heating are necessary. The course of phase transitions of the studied alloys determine their applications. Practical implications: The obtained results can be applied into the practice of processing and thermomechanical treatments of NiTi alloys designed for the production of shape memory medical implants and devices which act under the influence of the human body heat. Presented are the conditions of thermomechanical treatment to obtain a wide temperature range for the R-phase existence in the investigated alloys. Originality/value: The paper presents new results of optimization of the thermal treatment of NiTi shape memory alloys to obtain the reversible B2 ↔ R transformation used to prepare new shape memory implants and medical devices which exhibit shape recovery at a narrow temperature range below the human body temperature. In this paper it was shown that the temperature X-ray diffraction method can be used for the visualization of transformation courses and obtaining characteristic temperatures of transformations.

4

Rentgenowska analiza fazowa proszków i spiekanych kompozytów. Stal szybkotnąca-węglik WC-miedź.

Leżański J., Madej M., Ratuszek W.

Rudy i Metale Nieżelazne

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2003

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R. 48, nr 4

180-183

PL

Przedstawiono wyniki rentgenowskiej analizy fazowej proszków stali szybkotnącej gatunku M3/2, węglika WC, miedzi fosforowej oraz uformowanych z nich metodą prasowania i spiekania w próżni kompozytów. W kompozytach stwierdzono obecność składników fazowych występujących w proszkach, za wyjątkiem fosforku Cu3P oraz węglika W2C w kompozytach stal szybkotnąca-węglik WC, nie zawierających miedzi.

EN

Results of X-ray phase analysis of the powders from the M3/3 high-speed steel, WC carbide and phosphor copper, and of the composites formed from them by pressing and sintering in a vacuum, have been presented. The phase components present in the powders were found in the composites, except for Cu3P phosphide and W2C carbide in the high-speed steel- WC carbide composites, which did not comprise copper.

5

Elektroosadzanie kompozytowych warstw niklowych utwardzanych dyspersyjnym wolframem.

Serek A., Budniok A.

Archiwum Nauki o Materiałach

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1999

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T. 20, nr 4

259-268

PL

Kompozytowe warstwy elektrolityczne niklu o grubości 30-200 mikrometrów zawierające zdyspergowany wolfram otrzymywano z elektrolitu Wattsa z dodatkiem zawiesiny płynu wolframowego. Proces elektroosadzania prowadzono w warunkach galwanostatycznych przez 30 min, 60 min i 120 min w warunkach ciągłego mieszania mechanicznego w temperaturze 298 K. Przeprowadzono rentgenowską analizę fazową, badania morfologii powierzchni warstw, a także określono skład chemiczny i miHV na szlifach poprzecznych warstw. Stwierdzono, że warstwy charakteryzują się obecnością dwu oddzielnych faz - niklu i wolframu, a grubość warstwy, jej skład chemiczny i twardość są funkcją czasu osadzania.

EN

Electrolytic nickel composite layers with dispersed tungsten were obtained from Watts type electrolyte containing a suspension of tugsten powder. The process of electrodeposition was carried out under galvanostatic conditions for 30, 60 and 120 min - at 298 K with intensive mechanical stirring (150 rpm) to maintain the tungsten powder in suspension. The study of the obtained layers included examination of thickness, surface morphology, muHV hardness on a cross-section, chemical composition and X-ray phase analysis. It was found that the investigated layers are characterized by the presence of two separated nickel and tungsten phases and their thickness, hardness and chemical composition are the function of the deposition time.