This paper deals with various selective laser melting (SLM) processing strategies for aluminum 2618 powder in order to get material densities and properties close to conventionally-produced, high-strength 2618 alloy. To evaluate the influence of laser scanning strategies on the resulting porosity and mechanical properties a row of experiments was done. Three types of samples were used: single-t...

A vertex-irregular total k-labelling λ : V (G)∪E(G) −→ {1, 2, ..., k} of a graph G is a labelling of vertices and edges of G in such a way that for any different vertices x and y, their weights wt(x) and wt(y) are distinct. The weight wt(x) of a vertex x is the sum of the label of x and the labels of all edges incident with x. The minimum k for which a graph G has a vertex-irregular total k-lab...

Near fully dense tungsten coatings onto molybdenum substrates have been demonstrated using the Supersonic Laser Deposition (SLD) process. This is a characteristic that is not readily achievable with refractory materials. The tensile strength of the tungsten deposited coatings, 724MPa, is comparable to that of wrought tungsten with no evidence of melting or substrate grain growth. The results ha...

sound power is considered as an excellent measure for evaluating the efficiency of noise controls as well as for comparing noise sources in workrooms. this parameter can be determined by sound pressure or intensity based methods in real conditions of workrooms. this paper aims empirically to compare these in situ methods in relation to a typical industrial machine located in workroom in terms o...

bis(2-r-ind)zrcl2 (r: h or phenyl) was supported on different types of silica by in situ impregnation method and used for ethylene polymerization. in this method, the step of catalyst loading on support was eliminated and common alkyl aluminum (triisobutylaluminum, tiba) cocatalyst was used instead of expensive methyl aluminiumoxane (mao) cocatalyst in the polymerization. the effect of surface ...