Liana Baltes

The Effect of Laser Shock Processing on Corrosion Resistance of Stainless Steel AISI 316L

The paper presents the effect of laser shock processing on stainless steel 316L corrosion resistance. The samples were laser welded and mechanical treated using a Nd:YAG laser with a 1064 nm wavelength, and two different pulse density: 900 pulse/cm2 and 1600 pulse/cm2. After the laser shock processing, the samples were subjected to a seawater solution for corrosion testing. The curves obtained were statistically modeled using Stern-Geary equation. One may observe that the corrosion speed of the LSP samples treated with 900 pulse/cm2 is eight times higher than the corrosion speed of the LSP samples treated with 1600 pulse/cm2.

Thermal and Thermorheologic Characterization of Different Polyolefin Waste Fractions

In this study, melt flow index values from several household waste fractions containing mainly polypropylene and high-density polyethylene, were measured at 190 °C for polyethylene and 230 °C for polypropylene-rich fractions. High values of MFI (low shear viscosities) have been reported probably due to the lower molecular mass of the polymer waste and/or the presence of surfactant compounds on the surface of the polymer flakes. Also, by extruding the same batch in different cycles at the same temperature values, the number of processing cycles on which the polymer could be recycled has been determined.

Mechanical Properties and Microstructure Aspects of AlSi10Mg Casting in Vibrating Field

Aluminum alloys are one of the most extended groups of functional materials by reason of combination between good mechanical properties and low mass. The aim of the present paper is to test the influence of the vibrations on the AlSi10Mg (EN 1706-2010) solidification. For comparison, six lots were casted in cold and preheating molds, with or without vibrations within 50 Hz and 1050 Hz. For each casting frequency was measured the silicon phase dimension, hardness, tensile stress and impact strength. The mechanical properties increase with the vibration frequency. Increasing the vibration frequency, the structure will be refined and also the size of the silicon phase is decreasing. Considering that one source of porosity is the gas entrapped or dissolved in the liquid metal during the casting, using vibration along casting and cooling allows it’s decreasing.

The Effect of Mo and Al on the Corrosion Behavior of Titanium and Some of its Alloys for Biomedical Applications

The influence of molybdenum and aluminum on the corrosion resistance of the Ti and other Ti-based biomedical implant alloys under simulated physiological conditions is presented. Ti and its alloys Ti-10Mo and Ti-10Mo-10Al were studied. The electrochemical impedance spectroscopy technique was used and the experimental results were compared with those obtained by potentiostatic and potentiodynamic techniques. All the measurements were made in Ringer ́s solution at different pH and at different potentials as Ecorr, -650, -500, 0, +200 and +400 mV vs SCE. It was evident that Mo improved passivity and limited the active corrosion of the β-phase of Ti while Al enrichment of the α-phase was found to be detrimental to the passivity and corrosion resistance of Ti. In most experimental conditions, the passive film is formed by TiO2, Ti2O3 and TiO. When pH is very low, thermodynamically stable state of Ti is titanium anion Ti3+.

URBAN WASTE MANAGEMENT IN BRASOV AREA

Waste is a component of human life, therefore is inevitable. The great hazard that is prevalent in our country is the fact that some types of waste are stored together with hazardous industrial waste. This is why the Agency of Environment Protection is focusing on managing waste efficiently in Brasov area. This way all the main contributors like the mayor’s office have their attention on, and want a resolution (even partial) to the most important adopted measures until 2007.