Ballistic penetration experiments have been performed on ceramic tiles laminated with thin layers of polymer in between. The experiment involves shooting a cylindrical rod made of a tungsten heavy alloy (WHA) against an unconfined ceramic/polymer laminated structure that is backed by a 6061-T6 aluminum alloy cylindrical-block, at a velocity ranging between 1000 to 1200 m/s. The residual depth of penetration in the aluminum block is used as a measure of the resistance offered by the laminated ceramic/polymer structure to ballistic penetration. Penetration resistance of the laminated ceramic/polymer structures is compared to that of monolithic ceramic structures of the same total thickness. Experimental results demonstrate that penetration resistance of an unconfined ceramic structure can be improved significantly by laminating ceramic tiles with thin polymer layers in between. This enhanced performance of the laminated structure is attributed to a reduced wave propagation (and damage) velocity in the laminated ceramic/polymer structure and also to the crack arresting feature of the polymer layer. r

No abstract

The wear behaviour of polytetrafluroethylene (PTFE) filled with 25% glass and 40% bronze particles was studied on a pin on disc test rig. Solid lubricant composite materials were prepared by compression moulding technique. The wear parameters considered for the study were applied load, sliding speed and sliding distance. The experimental results indicate that the weight loss increases with increasing load, sliding speed and sliding distance, as expected. Sliding distance has more effect on weight loss followed by applied load. The 40% bronzezPTFE composite exhibits better wear resistance compared to other types. The dominant interactive wear mechanisms during sliding of PTFE and its composites are discussed in this paper.

An attempt has been made to study the influence of wear parameters like applied load, sliding speed, sliding distance on the dry sliding wear of polytetrafluroethylene (PTFE), PTFE þ 25% glass and PTFE þ 40% bronze composites. Experiments, based on the techniques of Taguchi, were performed to acquire data in a controlled way. An orthogonal array and the analysis of variance were employed to investigate the influence of process parameters on the wear of composites. The worn surfaces were examined using scanning electron microscope (SEM). The experimental results show that sliding distance and applied load were found to be the more significant factors among the other control factors on wear. The objective is to establish a correlation between dry sliding wear of composites and wear parameters. These correlations were obtained by multiple regressions. A good agreement between the predicted and actual wear resistance was seen.

No abstract