The corrosion properties of iron-based composite materials containing graphite and silicon carbide (SiC) reinforcement were investigated. The effects of silicon carbide reinforcement were investigated by adding 0.5% graphite and 1%, 2%, and 4% SiC. A powder metallurgy method was used to produce the composite samples. Iron, graphite, and silicon carbide powders were blended for one hour with a three-axis mixer and then unidirectionally pressed under a pressure of 750 MPa. After pressing, the composite materials were sintered at 1100°C for one hour. The corrosion properties and microstructure, density, and hardness properties of the composite materials that can affect the corrosion properties were also investigated. It was determined that the pore ratio and hardness of the composite material increased, and corrosion resistance decreased, with increasing silicon carbide content.

ÖzBu çalışmada toz metalurjisi yöntemi ile üretilen alümina (Al2O3) takviyeli alüminyum esaslı kompozit malzemelerde mekanik alaşımlama süresinin tuzlu ortamdaki korozyon davranışına etkileri incelenmiştir. Numunelerin toz metalurjisi yöntemi ile üretiminde, takviye malzemesi olan Al2O3 tozları ve ana malzeme olan alüminyum tozları karışımına 1 saat karıştırma veya 2, 4, 6, 10 saat mekanik alaşımlama işlemleri uygulanmıştır. Presleme ve sinterleme işlemleri sonrasında elde edilen Al2O3 takviyeli alüminyum esaslı kompozit numunelere tuzlu ortamında (%3,5 NaCl) potansiyodinamik yöntem ile elektrokimyasal korozyon testleri uygulanmıştır. Çalışma sonucunda, mekanik alaşımlama süresinin artması ile Al2O3 takviyeli alüminyum esaslı kompozit malzemenin korozyon dayanımının azaldığı belirlenmiştir. AbstractIn the study, the effects of mechanical alloying duration on corrosion behavior of powder metal aluminum composites reinforced with alumina (Al2O3) were investigated in saltwater medium. For composite materials production, reinforcement Al2O3 powders and base metal aluminum powders were applied one hours mixing or mechanical alloying for 2, 4, 6 and 10 hours. After pressing and sintering treatment of composite powders, electrochemical corrosion tests were applied in saltwater solution (3.5 wt. % NaCl) by potentiodynamic methods. According to corrosion test results, corrosion resistance of composite materials was decreased with increasing of mechanical alloying duration.

Bu çalışmada, alümina (Al2O3) takviyeli alüminyum esaslı toz metal kompozit malzemeler, korozyon dayanımını geliştirmek amacıyla iletken polimer polipirol (Ppy) ile kaplanmış ve yapılan kaplama işleminin kompozit malzemenin korozyon davranışına etkileri incelenmiştir. Toz metalürjisi yöntemi ile üretilen alüminyum esaslı kompozit malzemenin polipirol kaplama işlemi, elektrokimyasal yöntem ile potansiyel taraması uygulanarak yapılmıştır. Kaplamasız ve dört farklı sayıda potansiyel taraması yapılarak polipirol kaplanan alümina takviyeli alüminyum esaslı kompozit numunelere potansiyodinamik polarizasyon yöntemi ile elektrokimyasal korozyon testleri uygulanmıştır. Çalışma sonucunda, alümina takviyeli alüminyum esaslı kompozit malzemenin uygun şartlar altında elektrokimyasal yöntem kullanılarak polipirol ile kaplanabildiği ve yapılan kaplamanın kompozit malzemenin korozyon dayanımını geliştirdiği belirlenmiştir.

In the study, the corrosion behavior of aluminum matrix composites reinforced with boron carbide (B4C), silicon carbide (SiC) and alumina (Al2O3) were investigated in saltwater (3.5 % NaCl). Composite materials were produced by powder metallurgy. For composite materials production, various reinforcement and aluminum powders were mixed by mechanical alloying for 4 and 10 hours. After mechanical alloying, mixed powders were compacted under 700 MPa pressure and sintered at 600 °C. Electrochemical corrosion tests were applied on specimens in the saltwater solution using potentiodynamic methods. According to the results of the investigation, the best corrosion resistance was obtained by aluminum/B4C and the lowest by aluminum/Al2O3 composites.

In this study, hardness and corrosion properties of alumina reinforced AA5083 aluminum alloy based functionally graded materials were investigated. The powder metallurgy method was used in functionally graded materials production and the samples were produced in 3, 4 and 6 layers. Vickers hardness tests and potentiodynamic corrosion tests were conducted on the samples of the produced functionally graded materials. It was seen that there was an increase in hardness values with increasing alumina reinforcement ratio in layers of functionally graded materials. According to corrosion test results, there was a small decrease in the corrosion rate of the materials with increasing number of layers in the functionally graded materials. Corrosion effect was found to be higher in layers with high alumina reinforcement.