Wyniki wyszukiwania - Biblioteka Nauki

1

Thermal barrier coatings manufactured by suspension plasma spraying - a review

100%

Łatka L.

|

tom Vol. 18, nr 3(57)

95--117

EN

Thermal barrier coatings (TBC) is one of the most intensively studied of coatings’ applications area. From 1970’s TBC are developed in two independent ways: (i) development in new materials, with lower thermal conductivity, better erosion resistance and better thermal shock resistance or (ii) development in new deposition techniques. On this field besides conventional atmospheric plasma spraying (APS) and almost conventional (because of very common use) EB-PVD method, in the past 20 years two new techniques have been developed, namely suspension plasma spraying (SPS) and solution precursor plasma spraying (SPPS). In this paper only SPS method was described, as well as, new materials, which could be used in industrial applications of TBC. Moreover, the key issues, like suspension preparation, type of suspension injection, interaction between liquid droplets and plasma jet and deposition mechanism were described.

2

Development in PTA surface modifications – a review

63%

Łatka L. , Biskup P.

|

tom Vol. 20, nr 2(64)

39--53

EN

Surface modification is one of the most intensively studied issue of technology, which is related to the almost all branches of industry. Since more than 100 years the huge number of methods has been developed and are still in growth. On this field the plasma transferred arc (PTA) hardfacing and surfacing is one of the most frequently used group of the method. The development of this method is going in three ways: (i) modification of the classic technique and the equipment, (ii) development in new materials, especially with the nanometric size and (iii) replacement dangerous materials (e.g. high cobalt alloys). In the current article the state of the art as well as the development directions of the plasma hardfacing issues are described.

3

Atmospheric plasma spraying of Al2O3 + 13% TiO2 coatings using external and internal injection system

51%

Łatka L. , Michalak M. , Jonda E.

|

tom Vol. 19, nr 4(62)

5--17

EN

The ceramic coatings based on mixture of Al2O3 and TiO2 have better properties in comparison to the pure alumina ones. Among many techniques, plasma spraying is very useful method of ceramic coatings manufacturing. In this paper, the results of microscopic, mechanical and tribological properties investigations of Al2O3 + 13 wt% TiO2 coatings manufactured by atmospheric plasma spraying are presented. The cylinder substrates made from stainless steel (X5CrNi18-10) had a diameter equal to 25 mm and thickness equal to 2 mm. The plasma spray experimental parameters included three variables: (i) type of injection system (external or internal), (ii) size of corundum particles for sandblasting and (iii) torch linear speed. The results confirm, that type of injection system is a dominant parameter. Internal injection results in better degree of particles melting, what influences on wear resistance performance, as well as higher values of bond strength.

4

Przygotowanie materiału wsadowego do natryskiwania plazmowego z zawiesin

51%

Michalak M. , Łatka L. , Sokołowski P.

|

tom Nr 3 (37)

18--22

PL

W artykule przedstawiono proces przygotowania materiału wsadowego (zawiesiny) do natryskiwania plazmowego z zawiesin (SPS). Ze względu na złożoność procesu SPS oraz postać zawiesiny (faza ciekła–rozpuszczalnik, faza stała–proszek oraz dodatki), przygotowanie materiału wsadowego istotnie wpływa na przebieg natryskiwania oraz jakość i właściwości wytworzonych powłok. Stabilna zawiesina ma kluczowe znaczenie w jakichkolwiek zastosowaniach praktycznych i każdy etap jej przygotowania wymaga szczególnej staranności.

5

Wpływ przygotowania powierzchni na elektronową emisję polową powłok TiO2 natryskanych plazmowo z zawiesin

51%

Znamirowski Z. , Kozerski S. , Łatka L. , Pawłowski L.

|

tom R. 88, nr 3

27--31

PL

W pracy badano elektronową emisję polową z powłok TiO2 na podłożach ze stali austenitycznej. Powłoki natryskiwano plazmowo z użyciem zawiesin. Zawiesiny sporządzano na bazie mieszaniny alkoholu etylowego 50% i wody 50%. Powierzchnie próbek toczono lub poddawano obróbce strumieniowo-ściernej. Stwierdzono, że emitery polowe natryskane na powierzchnie poddane wcześniej obróbce strumieniowo-ściernej charakteryzują się lepszą stabilnością emisji elektronowej.

EN

The electron field emission of TiO2 coatings on substrates made of austenitic steel has been investigated. Plasma sprayed coatings using suspensions. The suspensions were prepared based on a mixture of 50% ethyl alcohol and 50% water. The surfaces of the samples machined or subjected to abrasive blasting. It has been found that the field emitters been sprayed onto the surface before blasting, they have better stability of electron emission.

6

Cavitation erosion and sliding wear of MCrAlY and NiCrMo coatings deposited by HVOF thermal spraying

45%

Szala M. , Walczak M. , Łatka L. , Gancarczyk K. , Özkan D.

|

tom Vol. 20, nr 2(64)

26--38

EN

The investigation into wear resistance is an up-to-date problem from the point of view of both scientific and engineering practice. In this study, HVOF coatings such as MCrAlY (CoNiCrAlY and NiCoCrAlY) and NiCrMo were deposited on AISI 310 (X15CrNi25-20) stainless steel substrates. The microstructural properties and surface morphology of the as-sprayed coatings were examined. Cavitation erosion tests were conducted using the vibratory method in accordance with the ASTM G32 standard. Sliding wear was examined with the use of a ball-on-disc tribometer, and friction coefficients were measured. The sliding and cavitation wear mechanisms were identified with the SEM-EDS method. In comparison to the NiCrMo coating, the MCrAlY coatings have lower wear resistance. The cavitation erosion resistance of the as-sprayed M(Co,Ni)CrAlY coatings is almost two times lower than that of the as-sprayed NiCrMoFeCo deposit. Moreover, the sliding wear resistance increases with increasing the nickel content as follows: CoNiCrAlY < NiCoCrAlY < NiCrMoFeCo. The mean friction coefficient of CoNiCrAlY coating equals of 0.873, which almost 50% exceed those reported for coating NiCrMoFeCo of 0.573. The as-sprayed NiCrMoFeCo coating presents superior sliding wear and cavitation erosion resistance to the as-sprayed MCrAlY (CoNiCrAlY and NiCoCrAlY) coatings.