ORIGINAL RESEARCH ARTICLE | May 18, 2024
Microstructure Characteristic and Mechanical Properties of Copper Influenced Grey Cast Iron
Kutelu, B. J, Ogundeji, O. O, Oluyori, R. T
Page no 65-75 |
DOI: 10.36348/sjce.2024.v08i05.001
Grey cast iron (GCI) is characterized by brittleness, making it unsuitable for use in applications requiring high impact loading. Hence, efforts were made in this study to produce GCI with improved mechanical properties by addition of copper. Four samples were produced, the first sample was not alloyed (control), and the second, third and fourth were alloyed with 1.4wt.%Cu, 1.8wt.%Cu and 2.2wt.%Cu respectively. The samples were characterized using scanning electron microscope with EDS, and tested in tensile, hardness and impact. From the results, silicon contents of the alloyed samples are high relative to the control sample. The control and 2.2wt.%Cu alloyed samples are hypereutectic with carbon equivalent values (CEVs) of 4.391% and 4.200% respectively, while the 1.4wt.%Cu and 1.8wt.%Cu alloyed samples are hypoeutectic with CEVs of 3.940% and 3.600% respectively. The control sample is characterized by long graphite flakes, which are uniformly distributed within ferritic - pearlitic matrix. Graphite flakes of the 1.4 wt.% Cu and 1.8 wt.% Cu alloyed samples are uniformly distributed within pearlitic - ferritic matrix, while graphite flakes of the 2.2wt.%Cu alloyed sample are uniformly distributed within ferritic-pearlitic. Average graphite flake length of the control sample is high as compared to the copper alloyed samples, while graphite flake count of the control sample is low relative to the copper alloyed samples. Tensile strength characteristics of the copper alloyed samples are superior to the control sample. Optimum tensile strength characteristics (165.9 Nm2) was obtained at 1.4wt.%Cu. Ductile characteristic of the of control the sample is superior to ductile characteristics of the copper alloyed samples. Optimum ductility characteristic (3.82%) was obtained at 2.2 wt. %Cu. Hardness characteristics of the copper alloyed samples are superior to hardness characteristic of the control sample. Optimum hardness characteristics (61 HRB) was obtained at 1.4wt.%Cu. Impact strength characteristic of the control sample is low relative to impact strength characteristics of the copper alloyed samples. Optimum impact strength characteristics (78.93 KJ/m2) was obtained at 2.2wt.%Cu.