CAD/CAE application in centering EDM machine design
The centering EDM machine can be completed online centering hole processing. Traveling by the high speed line feed mechanism, low speed line feed mechanism, rotating body, lifting body, auto body for baseball, Swing components, such as buffer baffle. The advantage of this approach is: a small device, processing consistency, and efficient processing, process automation, and effective in the elimination round billet rolling wear puncher into a capillary formed by the iron handle. In order to design the machine, the CAD/CAE technology, basing on the conception of global structure, dwelling on selecting motor, 3D modeling with solidworks, dynamic simulation with cosmosmotion, and analysis the key parts using finite element method were presented.
Development of new material and heat treatment for tools ensuring high performance in hot seamless tube rolling
Abstract A new technology has been developed to improve the life of tools used for high temperature steel rolling in seamless tube manufacturing. It is a joint technology combining a new chemical composition and a special heat treatment. The new steel tool material has high Cr, C, and Ni contents compared with those of the conventional tools in order to increase the volume fraction of carbide which increases wear resistance. Through the new heat treatment, the macroscopic distribution pattern of eutectic carbide changes from meshlike to granular form increasing resistance against crack propagation. The validity of the results in the laboratory has been verified on the production line.
CATARACT: A HISTORICAL PERSPECTIVE.
The earliest extant description of a surgical operation for the cure of cataract is that of Celsus, toho practiced medicine in Rome at the beginning of the Christian era. In his text De Meclicina he described in detail his method of couching, by which he inserted a bronze needle into the eye at the equator on the lateral side of ihe globe and depressed the cataract downward into the lower part of the vitreous where the surgeon hoped it would remain out of the way of vision. The same method had been employed by the Greeks and Hindus for at least several hundred years earlier and ivas to continue as the only operation available until the middle of the eighteenth century when Daviel of Paris described extraction of the lens through the cornea. The early couchers worked on the premise that the crystallin humor we know as the lens was the receptor for vision, and that in certain conditions of disease a suffusion flowed doivn in front of the crystallin humor where it solidified and formed a dense curtain. The purpose of couching was to press the hardened corrupt humor out of the way of the lens. That cataract was opaque material within the lens itself was not recognized until after the middle of ihe seventeenth century. Until then ihe surgeons were not even aware that it was the lens they were dislocating.