Hardness of the widely used structural steel is of vital importance since it may help in the determination of many mechanical properties of a material under loading situations. In order to obtain reliable information for design, properties homogeneity should be validated. In the current study the hardness variation over the different diameters of the same AISI 4140 bar is investigated. Measurem...

In this study, the effects of cutting edge geometry, workpiece hardness, feed rate and cutting speed on surface roughness and resultant forces in the finish hard turning of AISI H13 steel were experimentally investigated. Cubic boron nitrite inserts with two distinct edge preparations and throughhardened AISI H13 steel bars were used. Four-factor (hardness, edge geometry, feed rate and cutting ...

Austenitic stainless steels (ASSs) have an excellent corrosion resistance but relatively-low hardness and yield strength [1,2], leading to limited usage in applications that high values of hardness and wear resistance is necessary for material surface. Therefore, surface properties such as hardness must be improved using appropriate techniques. Mechanical surface treatments such as ultrasonic s...

Impagliazzo and Levin showed a reduction from average-case hardness of any NP-search problem under any polynomialtime samplable distribution to that of another NP-search problem under the uniform distribution in [12]. Their target was the hardness of positive instances occurring with probability 1/poly(n) under the distributions. In this paper, we focus on hardness of a larger fraction of insta...

INTRODUCTION For the construction of any dental prosthesis, accurate impressions are necessary. Hence, we undertook the present study to evaluate and compare the surface hardness of gypsum casts poured from impressions made using conventional alginate and self-disinfecting alginate. MATERIALS AND METHODS A total of 30 impressions of stainless steel die were made, out of which 15 impressions w...

Empirical hardness models predict a solver’s runtime for a given instance of an NP-hard problem based on efficiently computable features. Previous research in the SAT domain has shown that better prediction accuracy and simpler models can be obtained when models are trained separately on satisfiable and unsatisfiable instances. We extend this work by training separate hardness models for each c...

The present study was carried out to investigate the effect of alloying elements and thermo-mechanical treatment (TMT) i.e. hot rolling and forging with different reduction ratios on the hardness (HV) and impact toughness (J) of heat-treated low alloy steels. An understanding of the combined effect of TMT and alloying elements and by measuring hardness, impact toughness, resulting from differen...

Co-deposition of zinc metal matrix with ZnO composite was fabricated from electrolytic chloride based coating consisting of 20-40g/L ZnO particle. The resulting composite coatings were characterized using high optic microscope (OPM). The corrosion resistance properties of Zn-ZnO composite coatings were measure using linear polarization in 3.5% NaCl solution. The variation of amount of ZnO %wt. ...

Formulas governing fixed orbital hardnesses and their relation to the hardness kernel are derived. It is shown how the orbital hardness matrix and its inverse matrix, the orbital softness matrix, may thus be directly calculated, and then the total chemical hardness, softness, and electronegativity of a molecular species. These quantities are calculated for the molecule HCN, using Dirac exchange...

The factors necessary to obtain an optimal heat treatment that influence the hardness and resistivity of Al-6Si-0.5Mg casting alloys with Cu or/and Ni additions were investigated. The alloys were homogenised (24hr at 500C), solutionized (2hr at 540C) and artificially ageing at various times and temperatures. The alloys were aged isochronally for 60 minutes at temperatures up to 400C and isother...