The purpose of this research paper is to study the tool wear and surface roughness of AISI 8620 material using coated ceramic tool by turning process. Ceramic cutting tools have outstanding material hardness, resistance to high temperatures, wear resistance, chemical stability and hot hardness. Ceramic tool with Al2O3 + TiC (golden) coating was used to investigate the surface roughness and tool...

1 Abstract— The special characteristics and singular properties of diamond-like carbon (DLC) thin films deposited by pulsed DC plasma enhanced chemical vapor deposition (PECVD), such as hardness and wear resistance, are suitable for self assembly applications as protective coating and as nanostructured surfaces. In this master thesis project, nanostructured DLC surfaces will be designed and cha...

TiAlN/Al2O3 multilayers with different Ar/N2 ratios were deposited on Si substrates in different N2 partial pressure by magnetron sputtering. The crystalline and multilayer structures of the multilayers were determined by a glancing angle X-ray diffractometer (XRD). A nanoindenter was used to evaluate the hardness, the elastic modulus and scratch scan of the multilayers. The chemical bonding wa...

The paper demonstrates the correlation between the chemical composition of steel grades and the hardness as well as the formability of laser welds generated with modern automotive high strength steel grades. At the very low heat input of industrial laser welding and the resulting extremely high cooling rate, the weld hardness is fully controlled by the carbon content of the base materials and n...

Structural and dynamic properties of the building block of silica nanowires, (SiO2)6, are investigated by Born-Oppenheimer quantum molecular dynamics simulations. Thirteen conformers have been identified, seven of which have not been reported before. The energy component analysis shows that the lower electrostatic interaction differentiates the global minimum from the other structures. We also ...

The purpose of this study was to examine the characteristics of an innovative composite material for dental restorations based on silorane--a monomer with a new chemical composition, and thereby compare the examined characteristics against those of well-known methacrylate-based composites. Degree of conversion at 2-mm and 6-mm depths as well as hardness, modulus of elasticity, and creep resista...

Using the first-principles particle swarm optimization algorithm for crystal structural prediction, we have predicted a novel monoclinic C2/m structure for ZrB₃, which is more energetically favorable than the previously proposed FeB₃-, TcP₃-, MoB₃-, WB₃-, and OsB₃-type structures in the considered pressure range. The new phase is mechanically and dynamically stable, as confirmed by the calculat...

Sol-gel titania films were deposited on 316L stainless steel using titanium isopropoxide as a chemical precursor. Dipcoating was performed at withdrawal speeds of 6 mm/min, 30 mm/min, and 60 mm/min. Deposited gel films were heat treated in air at 80 ̊C, 100 ̊C, 300 ̊C, and 400 ̊C. The structural evolution of the coatings was evaluated by infrared reflection-absorption spectroscopy. The influence of...

OBJECTIVE The objective of the present study is to evaluate and compare the flexural strength, dynamic elastic moduli and true hardness (H(o)) values of commercial Vita In-Ceram alumina core and Vita In-Ceram matrix glass with the standard aluminous porcelain (Hi-Ceram and Vitadur), Vitadur N and Dicor glass and glass-ceramic. METHODS The flexural strength was evaluated (n=5) using 3-point lo...

Some exact conditions for the extremals of the electrophilicity index, ω = μ(2)/2η (Parr, R. G.; von Szentpály, L.; Liu, S. J. Am. Chem. Soc. 1999, 121, 1922), along an arbitrary reaction coordinate, have been carefully examined. Implications within the widely used finite difference approximation for the density-functional based reactivity descriptors, their relationship with the maximum hardne...