Properties of novel composite alloys used for the engine pistons

The article presents the results of the investigations cover novel composite silumins with new alloying additives, such as chromium and molybdenum (not yet used in this type of silumin) and increased content of nickel and copper. The samples strength tests were performed at room temperature (20°C) and at elevated temperatures (up to 350°C), and were carried out using the strength machine, equipped with the special climate chamber. The dimensional stability of the new aluminum alloy was investigated using the precision dilatometer. This device allows one to register and record the sample dimensions as a function of temperature, during sample heating and cooling. During the DTA crystallization process investigations, derivative curves have been determined, that allows the analysis of the solidification process and the analysis of the heat transfer process in the sample structure and phase transformations. In the article shows the derivative curve and representative microstructures, and characteristic temperatures for the conventional AlSi12 alloy and novel composite alloy. All research results indicated that the newly developed composite aluminum alloy has far better parameters than aluminum alloys used previously for pistons of the internal combustion engines. This article concludes with a summary of the advantages of the new composite alloys.