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The β-Ti alloys have attracted the attention of researchers due to their excellent properties and their remarkable biocompatibility. The present study evaluated the mechanical behavior analysis (hardness, compressive strength, and modulus of elasticity) of the Ti-15Mo-W system. For experimental research, we chose the TiMo15 biocompatible alloy as a starting material. In order to improve the mechanical properties, we added tungsten amounts of 3.88 to 12.20 wt.% and analyzed the results obtained. The successive melting of the samples was done using a vacuum arc furnace in a copper crucible cooled with water. Following micro-structural investigations, we found this alloy possessed a homogeneous structure and showed β-phase predominance. The investigated alloys have good mechanical properties—the mean Vickers micro-hardness values are between 251 to 321 HV, the compressive strength values range from 717 to 921 MPa, and the modulus of elasticity is between 17.86 and 45.35 GPa. These results are compatible to the requirements of a metallic material for medical applications as artificial implant devices.

In the paper are presented the experimental researches made in order to obtain a new titanium alloy - Ti15Mo5W used for medical applications with improved mechanical characteristics and modulus of elasticity. In this regard Ti15Mo with addition of W alloy was designed with the intention of obtaining b-Ti phase stability. For this, we studied the influence of: the bond order, energy level of metal d-orbital, ratio of valence electrons/atom and influence of the addition of W. After designing the alloy compositions and setting the parameters, the Ti15Mo5W composition was chosen to run the experiments. The experimental Ti15Mo5W alloy was obtained by vacuum arc remelting technique using Ti, Mo and W high purity metals. The alloy was characterized by SEM, EDS and tested for Vickers hardness and compression. The microstructural characterization of the alloy proved to be homogeneous, and the mechanical characterization highlighted the obtaining of an alloy with a low elasticity modulus of about 30 GPa and an average hardness of 320 HV.

Pyrometallurgical processing of lead ores generates large amounts of slag which is stockpiled as chunk or granules. Romanian dump heaps of such slag produced in the period 1972-1998, occupy an area of 4522 m 2 and a volume of 6616 m 3 . To assess the possibility of using this material in road construction, a complex characterisation of this waste has been carried out. X-ray diffraction, microcompositional and microstructural analysis revealed the presence of Fe, Zn, Pb, Cu sulfides, Fe, Ca, Si oxides and complex Mg, Al silicates etc. Following investigations were drawn several conclusions. According to the analysis of leachate specific indicators for the three types of slags analyzed (cooled slowly lead slag; granulated lead slag; deposited lead slag), granulated lead slag has the lowest lead content; value that exceeds the maximum allowed (current legislation). Analysis of acid drainage revealed that cooled slowly lead slag is not acid generating, granulated lead slag is uncertain and deposited lead slag is acidgenerating. To determine the physico-mechanical and geotechnical properties Proctor compaction test, Californian index CBR test, permeability test and direct shear test were performed. Results from these investigations show an approximation of the values of granulated slag and sand.