Production and characterization of aluminium matrix composites via pressureless sintering

In this thesis, pressureless sintering and charachterization of TiB2 particulate reinforced aluminium matrix composites were studied. As a matrix material 96% Al ? 4% Cu alloy was used. Al-TiB2 powder mixtures containing 10%, 15%, 20% and 30% TiB2 by volume were prepared and were cold pressed uniaxially at 800 MPa. Pressureless sintering was performed in a nitrogen gas atmosphere at 620 oC. Obtained composites were subjected to density measuretments, microstructral examinations, 3 point bending tests, hardness tests and wear resistance tests. Same tests were repeated after age hardening of the composites. After age hardening treatment, unreinforced sample presented a maximum 3 point bending strength of 940 MPa, 28% strain and 100 HB10 hardness value. Wear rate was 12,16 ± 3,16 x 10-3 mm3 / N.m in the unreinforced sample. The least wear rate was seen in 20% TiB2 containing samples. This composite presented 867 MPa bending strength, 7,41% strain and 130 HB10 hardness.