Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Mechanical, tribological and electrical properties of Cu-CNT composites fabricated by flake powder metallurgy method

Akbarpour M. R., Alipour S, Farvizi M., Kim H. S.

Archives of Civil and Mechanical Engineering

2019

Vol. 19, no. 3

694--706

Cu-CNT composites were fabricated by a flake powder metallurgy method, and their microhardness, electrical conductivity, frictional and wear properties were investigated. Homogenous distribution of CNTs in fine-grained Cu matrix was obtained using this process. Microhardness increased with the addition of CNT vol% up to 8% to the Cu matrix, while the conductivity decreased to 79.2 IACS %. Results showed that CNTs play a major role in improving wear resistance by forming a CNT-rich film that acts as a solid lubricant layer. In the synthesized composites, Cu- 4 vol% CNT composite exhibited the best wear and friction properties. The dominant wear mechanisms for the Cu-CNT composites were plastic deformation, abrasion, and flake formation-spalling. Also, a newly modified correlation was proposed for the theoretical calculation of the friction coefficient of Cu-CNT composites consisting agglomerated CNTs.

Challenges of Using Elemental Nickel and Titanium Powders for the Fabrication of Monolithic NiTi Parts

Farvizi M.

Archives of Metallurgy and Materials

2017

Vol. 62, iss. 2B

1075--1079

Due to its interesting properties and wide applications in different industries, fabrication of monolithic NiTi with cost-effective methods is an important and attractive issue. One of the economic ways to fabricate NiTi is employing elemental nickel and titanium powders. In this study, effects of using elemental powders as a precursor on the microstructure and mechanical properties of HIP-consolidated NiTi samples will be explored. The result of XRD analysis showed that after HIP process an interwoven structure which consists of NiTi2, Ni3Ti and B2-B19′ NiTi evolves. The formation of NiTi2/Ni3Ti intermetallics is thermodynamically favored which affects different aspects of this alloy: (i) it alters martensitic transformation temperatures; (ii) restricts essential properties of this alloy such as PE and SME, (iii) increases hardness, and (iv) yields to premature fracture at small strains during tensile tests.