No abstract

No abstract

The local heat transfer measurements in the cooling flow passage having both flat surface and semi-cylindrically grooved surface geometries inside the automobile disc brake were made. A uniform wall heat flux boundary condition on both surface geometries was created using gold film Intrex. Liquid crystal was used to measure the surface temperature. The experiments were made at Reynolds number (based on the hydraulic diameter of the rectangular duct) of Re=23,000, groove pitch-to-width (P/D) from 3 to 7, and groove depth-to-width (H/D) from 0.15 to 0.2. The results show that the magnitudes in the average Nusselt number on the grooved surface are maximum 92.8% higher than those on the flat surface without groove. A computer program utilizing the coupled FEM numerical technique that can predict the temperature distributions on the disc brake to analyze the thermal deformation has been developed.

Powder Metallurgy (P/M) is mainly composed of four steps: powder feeding, compaction, ejection, and sintering. A feedshoe moves forward and backward over the die cavity to fill it with metal powders. Possible problem in this stage is the uneven supply of powder on the horizontal direction. It can cause tool breakage due to uneven density distribution. Unevenly-distributed powder also causes internal cracks during compaction or warpage during sintering. Another problem during powder feeding is the inclusion of air with powder. This changes the overall density of the part. Powder feeding mechanism is very important, because it is the first step in the process. If there is imperfection during powder feeding, the final part ends up with a bad part no matter how perfect the rest of the processes are. This paper describes the development of an advanced powder feeding mechanism, which allows well-distributed amount of powder to be delivered to the die cavity.

No abstract