Steels. Micrographic determination of the apparent grain size

AbstractSterilization is a necessary step for all implant materials. Different methods can influence the materials properties. Especially important for magnesium as degradable materials is the determination of the corrosion properties. In this study the influence of 70% ethanol, glutaraldehyde, autoclaving, dry heat, UV-, gamma- and electron beam-irradiation on mechanical and corrosion parameters were analyzed. As mechanical parameters hardness and grain size were determined. The corrosion rate under physiological conditions, weight of the corrosion layer and corrosion morphology was determined. It could be demonstrated that irradiation treatments and 70% ethanol are suitable methods, as they decrease the corrosion rate. Heat-introducing methods (autoclaving and dry heat) acted as incomplete ageing treatments on this alloy and therefore increased the corrosion rate. Furthermore, osmolality showed a better correlation to the actual corrosion rate than the pH. Therefore an optimum ratio between alloying system, implant and sterilization method has to be established, depending on the intended application.

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Research on Fuel Migration Phenomenon in the Sintering Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.634-638.857 ◽

2013 ◽

Vol 634-638 ◽

pp. 857-863

Author(s):

Ya Ping Mo ◽

De Qing Zhu ◽

Jun Li

Keyword(s):

Grain Size ◽

Solid Fuel ◽

Fine Particles ◽

Vertical Direction ◽

Size Composition ◽

Fuel Particle ◽

Sintering Process ◽

Material Layer ◽

Flow Through

In this paper, we use the research methods of sintering cup.On the basis of the determination of solid fuel particle size composition and the distribution in the mixture. During the sintering process, respectively, 5min, 10min, 15min, 20min interrupt the test, by dectecting the distribution of solid fuel in the mixture to study the migration phenomenon of solid fuel during the sintering process. The results showed that: during the sintering process, the main migration of the fuel is the migration of fine particles, including the fuel migration of 0.25-0.5mm grain size, part of the 0.5-1mm grain size and a small amount of-0.25mm grain size,but most of the fuel migrated will be re-adsorbed, about 0.11% of the fuel with the air flow through the material layer, the migration of fuel to ease the state of segregation in the vertical direction along the material layer, so that cause actual participation in the combustion of the fuel content in line along the height direction of the material layer.

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