In this paper, aluminium alloy of grade ADC-12 was considered as a base metal and chromium carbide (Cr3C2) particles were reinforced through friction stir process. A detailed analysis of mechanical property and metallurgical characterization studies were performed to evaluate the surface composite. Remarkable changes were observed in the developed composite due to the mechanical force produced by the stir tool with an increase in hardness. The metallurgical investigation infers that the presence of silica in ADC-12 alloys has undergone mechanical fracture and long needle structure changed to reduced size. On the other hand, at higher tool rotational speed, the uniform distribution of hard particles was confirmed through SEM micrographs. Thus the modified surface composite has produced good mechanical property with high metallurgical qualities.
The paper analyses the as-cast state structure of chromium cast iron designed for operation under harsh impact-abrasive conditions. In the process of chromium iron castings manufacture, very strong influence on the structure of this material have the parameters of the technological process. Among others, adding to the Fe-Cr-C alloy the alloying elements like tungsten and titanium leads to the formation of additional carbides in the structure of this cast iron, which may favourably affect the casting properties, including the resistance to abrasive wear.
The results of research on stereological parameters of carbides in modified hypoeutectic chromium cast iron were shown in the paper. The
effect of distance the casting heat centre of casting to the carbide phase morphology was examined. The samples for metallographic
examination were taken from various locations of the model casting prepared in a special tester. This model casting was designed to
simulate the solidification of heavy castings. Using the proposed methodology the relation of the distance from the model mould and the
size, perimeter, length, width and the shape factor of carbides was examined. During the analysis, the values of stereological parameters of
carbides changed on various sections of the model casting.