Showing 2 results for Sedghi
Sedghi A., Shokouh Far A., Eslami Farsani R.,
Volume 2, Issue 3 (Apr 2005)
Abstract
Carbon fibers are fabricated from different materials such as special polyacrylonitrile (PAN) fibers, cellulose fibers and pitch. But PAN fibers are recognized as the most widely used precursor for the present-day manufacture of carbon fibers. The process of fabrication carbon fibers from special PAN fibers is composed of two steps including oxidative stabilization at low temperature and carbonization at high temperatures in an inert atmosphere. Today carbon fibers are still expensive because of the high price of their raw material (special PAN fibers).This study focuses on making carbon fibers from commercial PAN fibers (low price PAN fibers used in textile industry). The results shows that in case of conducting complete stabilization process, it is possible to produce desirable carbon fibers from commercial PAN fibers. With some changes in conventional procedure of stabilization in terms of temperature and time of operation, the desirable conditions of complete stabilization are achieved.
A. Sedghi, R. Vahed,
Volume 11, Issue 4 (December 2014)
Abstract
Mechanically Activated Self-propagating High temperature Synthesis (MASHS) is the method which is used to promote self-propagating synthesis by increasing activity of reactants and increase the purity of products. In this study Ti 2 AlC and Ti3AlC2 max phases were synthesized by using mechanically activated self-propagating high temperature synthesis (MASHS) and samples reactivity and phase structure of samples was studied. This process was performed by combination of short duration ball milling (MA) of reactants (Ti, Al and C as raw materials) and selfpropagating high temperature synthesis (SHS) by microwave or furnace. Mixtures of Ti/Al/C by mole ratio of 2:1:1 and 3:1:2 were milled for 2h., then exothermic reaction was initiated in microwave or high temperature furnace and their reaction behavior and structure have been investigated by DTA and XRD. Results revealed that it’s possible to fabricate these materials by MASHS method but purity of them depends on type of reaction condition. DTA and XRD analyses proved that increasing of soaking time did not improve purity of compounds and some impurities such as TiC would be formed in non-optimized reaction routes.
