Engineering Commons^™

Indentation Behavior Of Superelastic Hard Carbon, Olga Chernogorova, Ekaterina Drozdova, Iraida Ushakova, Evgenii Ekimov, Vicente Benavides, Aleksander Soldatov

Nanomechanical Testing in Materials Research and Development V

Supererlastic hard carbon particles up to 1 mmin size were produced by fullerene collapse upon high-pressure high-temperature treatment with simultaneous sintering of metal-matrix composite materials (CM) reinforced by such particles. The hardness of carbon particles can be varied in a wide range by changing the parameters of their structure, which consists of curved graphene planes or their packets of different sizes. Such carbon phase was called “nanoclusterd graphene phase” (NGP) [1]. The properties of the carbon particles were controlled by changing treatment pressure (5 and 8 GPa) and temperature (1100-1800 K), composition of parent fullerites (C60 or C60/70), and pre-treatment …

Growing Larger: Scaling Up During Spark Plasma Sintering Of High– Temperature Ceramics, Oleg Vasylkiv

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

Recently, extensive efforts were made towards investigation and development of spark plasma sintering (SPS) as a promising technique for rapid densification of ceramics at relatively low temperatures. In this respect, SPS was used for various processes and materials including fabrication of bulk metals and ceramics and their composites. Furthermore, this ‘low temperature’ processing allowed consolidation of ceramics with strong covalent bonding to the full density. However, significant gap exists between the technological and fabrication achievements to the fundamental understanding of the SPS mechanisms. This gap is due to the complexity of the thermal, electrical and mechanical processes that may be …

Cryogenic Processing Of Al 7050-T7451 Alloy For Improved Surface Integrity, Bo Huang

Theses and Dissertations--Mechanical Engineering

Al 7050-T7451 alloy with good combinations of strength, stress corrosion cracking resistance and toughness, is used broadly in the aerospace/aviation industry for fatigue-critical airframe structural components. However, it is also considered as a highly anisotropic alloy as the crack growth behavior along the short transverse direction is very different from the one in the long transverse direction, due to the inhomogeneous microstructure with the elongated grains distributed in the work material used in the sheet/plate applications. Further processes on these materials are needed to improve its mechanical and material properties and broaden its applications.

The material with ultra-fine or nano …