Abstract:
Pakistan Navy Dockyard has been undertaking repairs, rebuild and modernization of wide range of PN assets. The organization has evolved into state of the art engineering complex over the years. However, there are few areas being continuously upgraded/modernized and foundry setup is no exception. As the requirement dictates, PN Foundry shop at PN Dockyard is a small setup primarily fabricating/manufacturing non-ferrous parts such as propellers for 40 men utility boats, pump impellers, valve bodies, valve flaps, pipe flanges, motor covers etc not on a much larger scale. Being a small setup not operationally involved in repairs of PN assets, however, the technology still needs review due factors enumerated in the ensuing paragraphs.
The purpose of this thesis was to propose a framework for eliminating or minimizing defects in casting process at PN Foundry which primarily consist of blow holes, shrinkage, hot tears, deformation, run outs, rough surface, swelling, pinhole, cold shuts, cold cracks etc. In this thesis a root cause analysis has been undertaken of various defects. A remedy and corrections has been applied on various castings to minimize defects, A comparative analysis with master part (free of defects) has been carried out after eradication of various defects. 10 castings attempts have been made on 25 kg High Tensile Brass Propeller and a very close solution to the master part has been reached.
A framework has been incorporated through documenting step wise improvements for future implementation as a whole for all foundry related products. Thesis report will be forwarded to higher authorities for formal approval/upgradation of equipment where needed and capacity/skill enhancement of HR. The process of upgradation does not stop here as the work will be further taken forward through capacity building in simulation softwares for mold design and subsequent castings.
