Wyniki wyszukiwania - BazTech

1

Applying Surface Plasma Hardening for Improving the Tribological Characteristics of Steel Parts

Rahadilov Bauyrzhan, Zhurerova Laila, Sagdoldina Zhuldyz

Tribologia

|

2019

|

nr 1

49--55

EN

This work presents the results of experimental studies on the application of surface plasma hardening to improve the tribological characteristics of steel marks of 40CrNi, 20Cr2Ni4A, and 34CrNi1Mn. According to the obtained results, it was established that, after plasma treatment, a modified layer with a thickness of 1–1.2 mm with high hardness and wear resistance is formed, consisting of a hardened layer of fine-grained martensite and, an intermediate layer of perlite and martensite. It was determined that, after treatment with a heating time of 3 min, the microhardness of steels 40CrNi and 20Cr2Ni4A doubles, and the steel 34CrNi1Mn increases 1.6 times, depending on the initial state, and the wear resistance of all steel samples increases, on average, 30 times.

PL

W niniejszej pracy przedstawiono wyniki eksperymentalnych badań nad stosowaniem utwardzania plazmy powierzchniowej w celu poprawy charakterystyki tribologicznej próbek stalowych 40CrNi, 20Cr2Ni4A i 34CrNi1Mn. Zgodnie z uzyskanymi wynikami ustalono, że po obróbce plazmowej powstaje zmodyfikowana warstwa o grubości 1–1,2 mm o dużej twardości i odporności na ścieranie, składająca się z utwardzonej warstwy drobnoziarnistego martenzytu i warstwy pośredniej z perlitu i martenzytu. Stwierdzono, że po obróbce z czasem ogrzewania 3 min mikrotwardość stali 40CrNi i 20Cr2Ni4A podwaja się, a stal 34CrNi1Mn wzrasta 1,6 razy, w zależności od stanu początkowego, i odporność na zużycie wszystkich próbek stali wzrasta średnio 30 razy.

2

Microscopic Analysis of Layers Containing Mg2Si and Mg17Al12 Phases Fabricated on AZ91 Through Thermochemical Treatment

Mola R., Cieślik M.

Archives of Foundry Engineering

|

2019

|

iss. 3

119--124

EN

The thermochemical treatment applied to improve the surface properties of AZ91 consisted in heating the material in contact with AlSi10Mg powder at 445 oC for 30 min. During heat treatment process the powder was held under pressure to facilitate the diffusion of the alloying elements to the substrate and, accordingly, the formation of a modified layer. Two pressures, 1 MPa and 5 MPa, were tested. The resultant layers, containing hard Mg2Si and Mg17Al12 phases, were examined using an optical microscope and a scanning electron microscope equipped with an energy-dispersive X-ray spectrometer (EDS). The experimental data show that the layer microstructure was dependent on the pressure applied. A thicker, three-zone layer (about 200 μm) was obtained at 1 MPa. At the top, there were Mg2Si phase particles distributed over the Mg17Al12 intermetallic phase matrix. The next zone was a eutectic (Mg17Al12 and a solid solution of Al in Mg) with Mg2Si phase particles embedded in it. Finally, the area closest to the AZ91 substrate was a eutectic not including the Mg2Si phase particles. By contrast, the layer produced at a pressure of 5 MPa had lower thickness of approx. 150 μm and a two-zone structure. Mg2Si phase particles were present in both zones. In the upper zone, Mg2Si phase particles were regularly distributed over the Mg17Al12 intermetallic phase matrix. The lower zone, adjacent to the AZ91, was characterized by a higher volume fraction of Mg2Si phase particles distributed over the matrix composed mainly of Mg17Al12. The alloyed layers enriched with Al and Si had much higher hardness than the AZ91 substrate.

3

Nanostructured composite materials on the base of titanium and zirconium with modified surface layers for medicine and engineering

Sharkeev Y. P., Kukareko V. A., Legostaeva E. V., Byeli A. V.

Scientific Problems of Machines Operation and Maintenance

|

2010

|

Vol. 45, nr 1

45-52

EN

This paper presents the results of the investigations of mechanical and tribological properties of ultrafine-grained and nanostructured titanium and zirconium under microplasma and ion beam treatments. It indicates that the nitrogen ion beam treatment of titanium and zirconium at low temperatures essentially increases the wear resistance by 35-50 times and reduces the friction coefficient by 40 percent. The biocomposite (nanostructured titanium - calcium phosphate coating) demonstrates a high friction coefficient (0.4-1.0) in tribological interaction with an ultrahigh molecular polyethylene imitated of subcutaneous tissue and bone tissue that allows to eliminate the microdisplacements of an implant against bone tissue under friction and to increase its fixation. A considerable improvement of tribological characteristics of the nanostructured titanium and zirconium with the modified surface layers give the advantages for these materials in medicine and engineering.

4

Domieszkowanie warstwy wierzchniej cegły węglikiem tantalu za pomocą światła lasera rubinowego

Klemm K., Klemm P., Rożniakowski K.

Fizyka Budowli w Teorii i Praktyce

|

2010

|

T. 5, nr 3

21-25

PL

W pracy przedstawiono charakterystyczne wyniki badań domieszkowania warstwy wierzchniej cegły pochodzącej z obiektów zabytkowej Łodzi przemysłowej. Proces domieszkowania przeprowadzono za pomocą światła lasera rubinowego pracującego w układzie generacji swobodnej. Jako substancji domieszkującej użyto węglika tantalu w postaci proszku. Zaobserwowano w obszarze laserowego oddziaływania obszary w których węglik tantalu został wtopiony w warstwę wierzchnią a także obszary, w których występuje zjawisko laserowego platerowania.

EN

The work presents the results of experimental examinations of the chemical composition of the brick samples (covered of tantalum carbide) before laser beam interaction. The samples are genesis from Łódź old age buildings, placed Wólczańska 215 street. The electron microscopy (SEM) end Energy Dispersive X-ray methods were used. Large differences between chemical composition of the surface layer melted by laser beam and before laser exposition were observed.