Abstract: In this study we propose a novel monitor hydraulic
automatic gauge control (HAGC) system based on fuzzy feedforward
controller. This is used in the development of cold rolling
mill automation system to improve the quality of cold strip. According to features/ properties of entry steel strip like its average
yield stress, width of strip, and desired exit thickness, this controller realizes the compensation for the exit thickness error. The traditional methods of adjusting the roller position, can-t tolerate the variance in
the entry steel strip. The proposed method uses a mathematical model
of the system together with the expert knowledge to perform this adjustment while minimizing the effect of the stated problem. In
order to improve the speed of the controller in rejecting disturbances
introduced by entry strip thickness variations, expert knowledge is added as a feed-forward term to the HAGC system. Simulation
results for the application of the proposed controller to a real cold mill show that the exit strip quality is highly improved.
Abstract: In this paper the combination of thermal oxidation and
electrochemical anodizing processes is used to produce titanium
oxide layers. The response of titanium alloy Ti6Al4V to oxidation
processes at various temperatures and electrochemical anodizing in
various voltages are investigated. Scanning electron microscopy
(SEM); X-Ray Diffraction (XRD) and porosity determination have
been used to characterize the oxide layer thickness, surface
morphology, oxide layer-substrate adhesion and porosity. In the first
experiment, samples modified by thermal oxidation process then
followed by electrochemical anodizing. Second experiment consists
of surfaces modified by electrochemical anodizing process and then
followed by thermal oxidation. The first method shows better
properties than other one. In second experiment, Surfaces modified
were achieved by thicker and more adherent thick oxide layers on
titanium surface. The existence of an electrochemical anodized oxide
layer did not improve the adhesion of thermal oxide layer. The high
temperature, thermal formation of an oxide layer leads to a coarse
oxide grain morphology and a complete oxidative particle. In
addition, in high temperature oxidation porosity content is increased.
The oxide layer of thermal oxidation and electrochemical anodizing
processes; on Ti–6Al–4V substrate was covered with different
colored oxide layers.