Fabrıcatıon Of Aa6061 Reınforced Wıth B4c Metal Matrıx Composıtes And Investıgatıon Of Mechanıcal Propertıes And Ballıstıc Performances


Thesis Type: Doctorate

Institution Of The Thesis: Gazi University, Turkey

Approval Date: 2017

Thesis Language: Turkish

Student: Halil Karakoç

Supervisor: RAMAZAN ÇITAK

Abstract:

In this study, mechanical properties and ballistic performances of B4C particle reinforced AA6061 matrix composites produced by powder metallurgy were investigated. AA6061 matrix particles were mixed in varying ratio (0%, 5%, 10%, 15%, 20%, 25% and 30%, mass fraction) of B4C particle for 45 minute. These mixed powders were cold pressed under 400 MPa. The pressed compacts were sintered at 550 oC for one hour, and then were extruded at the same temperature. Extruded plate composite samples were produced by rolling the extruded samples at 200 oC. The T6 precipitation processes were applied to the composite samples for improving mechanical properties. The mechanical properties of the composites samples were characterized with hardness, tensile strength, transverse rupture strength and notch impact strength. Also, the ballistic performance of composite samples against 9 ×19 mm and 7.62×51 mm shootings were studied. As a result, the tensile and transverse rupture strength of samples increased with extrusion process compared to sintering process. The best mechanical properties were obtained with rolling process. The ballistic performance of the rolled samples against 9×19 mm shootings increased with increasing reinforcement ratio at the beginning, but it reduced with increasing reinforcement ratio due to increased hardness. Both extruded and rolled single plate samples show low ballistic performance against 7.62×51 mm shootings. The ballistic performance improves by using dual plate composite system against 7.62×51 mm shootings.