Investigation of low dielectric constant (k) films for deep sub-micron CMOS application.

Silica (Si02) thin film on Si with low dielectric constant (k) properties has been systematically prepared and investigated. Two types of this low-k material have been deposited on Si via sol-gel spin-on coating. Filem nipis silika (Si02) yang berpemalar dieletrik rendah endap di atas Si tlah disediakan dan dikaji dengan sistematik. Dua jenis film nipis telah disediakan menggunkan pemutaran sol-gel

Effect of alloying elements on properties of aluminide-base intermetallic material developed via powder metallurgy route.

The present study deals with the effect of additive element on structure and properties of Fe-Al intermetallic. FeAl-based intermetallic alloys with chromium or molybdenum addition were fabricated by s intering of mechanically alloyed powders

SPOT WELDING COPPER–1%Cr ELECTRODE TIPS PRODUCED VIA EQUAL CHANNEL ANGULAR PRESSING

A sharp 120o Equal channel angular pressing (ECAP) following rout Bc was applied at room temperature to refine the grains sizes of pure copper and copper-1%Chromium alloy for spot welding electrode tips application. Initially deformation behavior was investigated with the position using colorful plasticine as work piece followed by copper alloy. It was found the deformation at the central part of the work piece is heavily sheared than the outer part. Optical and Scanning electron microscopy were used to study the progress of grain refining under the influence of rotation and number of passes during pressing. The influnece of elongated fibrous nano graines on electrical conductivity and hardness were discussed. Shear test of spot welded 303 stainless steel indicated that nano structural Cu-1%Cr electrode tips used showed a superior results compared to commercial electrode

Alumina-mild steel friction welded at lower rotational speed

The joining of ceramic-metal can be done using different techniques such as brazing, diffusion bonding, and friction welding. However, the mechanism of ceramic-metal joining has still not been fully understood. In this study, an alumina rod was bonded to a mild steel rod via the friction welding technique by using an Al 1100 sheet as an interlayer. The diameters of the rods were both 10 mm, respectively. A friction pressure of 20 MPa and a forging pressure of 40 MPa were used. Rotational speed was maintained at 900 rpm and friction times from 2 to 20 s were applied. The joining strength was determined through a four point bending test. The maximum bending strength, 240 MPa was obtained when the friction time of 20 s was used. Under optical microscope and scanning electron microscope observation, the bonding aluminum interface was clearly obtained. Mechanical interlocking and close contact between the alumina-aluminum and aluminum-mild steel were observed at magnifications of 3000×. The strength of alumina-steel bonding is much dependent on the wettability of the alumina surface by the partially molten aluminum interlayer and the existence of mechanical interlocking between the interlayer and mild steel