Microscopic Observations Of Cross Sections Research Articles

Reinforcement of complete denture bases with continuous high performance polyethylene fibers

Clinical literature details the causes for deformation and failure of acrylic resin complete denture bases. These findings are used to select patterns of high performance polyethylene fiber reinforcement that would best use the properties of the material and improve the mechanical behavior of the prostheses. A technique is described for making reinforced maxillary and mandibular bases with the fibers placed as suggested by the analysis. Microscopic observations of cross sections of reinforced bases revealed good fiber/resin integration and polish.

Hydriding of an industrial Al2.7wt.%LiCuMgZr alloy

The absorption and desorption of hydrogen by AlLi alloys were investigated by thermogravimetry in the pressure range 0.1–3.0 MPa and the temperature range 150–350°C. The kinetic results complemented by microscopic observations of cross-sections show evidence of the formation, as a precipitate in the aluminium matrix, of a defined compound which turns out to be lithium hydride. The formation was controlled by the diffusion process in spherical symmetry. The pressure and temperature dependences were established.

Microscopic Observations of Cross Sections of Impacted Composite Laminates

Microscopic observations of cross sections of impacted [(0°)5/(90°)5/(0°)5] glass/epoxy composite laminates have been made using a scanning electron microscope. The microphotos obtained have confirmed macroscopic observations such as the initiation and propagation of the transverse cracks and delamination cracks and also given some details that cannot be obtained macroscopically. The transverse cracks are perpendicular to lamina interfaces when there is no delamination nearby, while transverse cracks grow obliquely to interfaces when they are accompanied by a delamination crack. Delamination cracking appears to interact with the observed transverse cracks.

The influence of the cutting speed on the mechanism of metal removal by an abrasive tool

The influence of the cutting speed (400–2000 m min −1) on the behaviour of the metal ahead of an abrasive tool face was investigated by microscopic observation of cross sections of the groove after rapid freezing of the cutting process. It was found that the position of the stagnant tip and the shape of the stagnant region of material produced ahead of the tool face varied with the cutting speed. The size of chip formed by an abrasive tool varied with cutting speed and this affected the metal removal rate of a grit.

Oxydation De L'alliage De Titane Ta6V4 Par L'oxygene Sec Entre 700°C Et 1000°C—I. Resultats Experimentaux

The oxidation kinetics of the titanium-base alloy Ti4V6Al was studied between 700 and 1000°C at several pressures of pure oxygen. The result shows a difference in oxidation behaviour between the Ti4V6A1 alloy and pure Ti at high temperatures. (The distinct kinetic law reported has numerous stages corresponding to successive accelerations and reductions in corrosion rate.) The study of the products formed (microscopic observation of cross-sections, examination of the distribution of elements with the microprobe) showed a stratified scale structure with several sublayers of A1 2O 3 parallel to the reaction front.