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Several materials have been used as surgical implants since the 16th century. Materials can be implanted in the human body; however, the choice of the appropriate material is based on the required mechanical, physical, chemical, and biological properties. Until now two classes of metals namely stainless steel and cobalt-chromium-molybdenum alloys became known as materials for implant applications. They were considered suitable for surgical implant procedures but many researchers and surgeons were not completely satisfied with their performance. The main problem of the modern science is to find a material that perfectly restores tissues damaged after accidents or diseases. The trend of the current research in orthopedic prosthesis is based on the development of titanium alloys composed of non-toxic elements with low modulus of elasticity. Powder metallurgy techniques have beenused to produce controlled porous structures such as the porous coating applied for dental and orthopedic surgical implants which allows bone tissue grown within the implant surface, improving fixation. The development of porous metallic biomaterials associated with their biomedical applications is an important research area. To obtain a good one implant successful therapy the composition, size, form and topography of the alloys are extremely important.

The use of pressed and sintered aluminum, obtained by the powder metallurgy route, to produce large quantities of near-net-shaped components is increasing rapidly in the automobile industry. The production of lightweight pieces of Al by powder metallurgy has attracted increasing attention due to its unique properties. Sintering helps develop mechanical strength and other properties in commercial alloys obtained by powder metallurgy. Sintering of Al can be achieved only upon formation of a liquid phase capable of destroying the extremely stable oxide layer on the surface of the Al particles. The aim of this investigation was to analyze the effect of compaction pressure on sintering of atomized ASTM 2124 type alloy. Powder characterization was carried out using scanning electron microscopy (SEM). The specimens were axially compacted at pressures of 500, 600 and 700 MPa. Differential scanning calorimetry (DSC) was carried out to determine the sintering temperature of the alloy powder. The specimens were sintered at 570° C. Characterization of the sintered material consisted of density measurements and optical as well as SEM examinations. Nevertheless, even the low recycling cost of Al , what increases its useful time and stabilizes its value, the large amount of energy required to obtain it reduce its application.

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In the present work, attempts of reducing a graphene oxide powder using a low temperature hydrogenation disproportionation desorption and the recombination process (L-HDDR) has been carried out. A lower processing temperature in large scale production is significant when costs are concerned. Graphite oxide was prepared using a modified Hummers’ method dispersed in ethanol and exfoliated using ultrasonication to produce Graphene Oxide (GO). Investigations have been carried out by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The experimental results of L-HDDR processing graphene oxide powder, using unmixed hydrogen at 400°C and relatively low pressures (<2 bars) have been reported. X-ray diffraction patterns showed a reduction of graphene oxide with the L-HDDR process. The results showed that both processes, the L-HDDR as well as the standard HDDR, may be applied to the reduction of graphene oxide in order to produce supercapacitor materials. The advantage of employing the L-HDDR process is a relatively low temperature reducing the cost of treatment, what is a very important factor for producing a large amount of material. Thus, the L-HDDR process has been considered a promising alternative method of reducing graphene oxide with efficiency, with the possibility of large scale production.