Productıon Of Functıonally Graded Materıal Composed Of Al7xxx/Sic Andalumınum Foam And Investıgatıon Of Its Mechanıcal And Ballıstıc Propertıes

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Thesis Type: Postgraduate

Institution Of The Thesis: Gazi University, Fen Bilimleri Enstitüsü, METALURJİ VE MALZEME MÜHENDİSLİĞİ ANABİLİM DALI, Turkey

Approval Date: 2017

Thesis Language: Turkish

Student: GÖRKEM KIRMIZI

Supervisor: HALİL ARIK

Open Archive Collection: AVESIS Open Access Collection

Abstract:

In this study, Al foam, which is foregrounded with the performance exhibited between porous materials, is included in the developed functional graded material (FGM) and functionally graded foam materials (FGFM) were produced by hot pressing for use as armor material. For this purpose, it has been aimed to develop protective armor which is minimally affected against ballistic attack and which is made to be foreground with lightness. In this context, Al7xxx and SiC powders were pressed at different temperatures (300 - 400 - 500oC) and pressure parameters (200 - 300 - 400 MPa) by powder metallurgy method and four stages of FGM containing SiC at rates of 15-30-45-60 % were produced, respectively, at each stage. Subsequently, FGM consisting of Al7xxx / SiC and 7xxx series materials of Al foam were produced together to obtain 5-stage ready to foam FGFM. The powder metal block samples obtained were subjected to foaming at 750 ° C to produce FGFMs. Al 7075 series of Al powder as the matrix material, TiH2 as foaming agent and ta SiC powders as reinforcement element were used. The resulting matrix / reinforcement interface state of the final product was examined by optical and electron microscopy (SEM). Transverse rupture strength, hardness and ballistic tests were performed to determine the mechanical features and V50 ballistic speed limit. As a result of the tests made, it was determined that the best results were obtained in FGFMs using production parameters of 500oC and 400 MPa. The specimens produced in these parameters were found to have the best matrix / reinforcement interface state, the highest hardness value at 193,66 HBW, the highest cross-sectional fracture strength at 704,58137 MPa, and the best ballistic performance. In the 30 degree ballistic tests conducted to determine the V50 speed limit, the V50 speed limit of the FGFMs was about 3 % higher than the value specified in the MIL-DTL-46063 standard.