StreszczenieW pracy przedstawiono wyniki spajania stopu EN-AC-44200 z materiałami kompozytowymi Al/Al2O3 z wykorzystaniem techniki zgrzewania tarciowego. Zastosowane materiały kompozytowe wytwarzano techniką ciśnieniowej infiltracji SC (ang. squeeze casting) oraz metodą iskrowego spiekania plazmowego SPS (ang. Spark Plasma Sintering). Zawierały one 20 oraz 30% objętościowego udziału fazy wzmacniającej -tlenku glinu, w różnej postaci. W przypadku kompozytów SC wzmocnienie stanowiły cząstki Al2O3 (α-form) o wielkości 3-6 μm, zaś dla kompozytów SPS był to elektrokorund gruboziarnisty o uziarnieniu 180 μm. W pracy przedstawiono optymalne parametry procesu zgrzewania tarciowego dla poszczególnych materiałów kompozytowych, opracowane przez autorów na podstawie analizy zmian mikrostruktury i twardości materiałów w obszarze spajania. Przeprowadzone badania miały na celu ocenę morfologii oraz jakości połączenia pomiędzy stopem 44200 a kompozytami Al/Al2O3 w zależności od rodzaju wzmocnienia oraz techniki wytwarzania kompozytów Al/Al2O3Słowa kluczowe: zgrzewanie tarciowe; kompozyt Al/Al2O3; Al2O3; stop Al AbstractThe paper presents results of bonding EN AC-44200 alloy with a different composite materials by friction welding technique. Materials used in the study, were processed using two techniques: squeeze casting (SC) and spark plasma sintering (SPS). It contained a 20% and 30% volume reinforced fraction of different forms of Al2O3. This paper presents the developed friction welding conditions of two different composite materials, and the analysis of microstructure and microhardness for obtained joints. All of studies were performed to determine the morphology and the quality of the connection between the 44200 alloy and Al/Al2O3 composites.

Friction welding is one of the most economical process for solid-state joining materials. This technique allows to weld similar and dissimilar materials in a very short time. Friction welding of metal with composites gives new possibilities of application, due to the fact that materials have different physical and mechanical properties. In the study, aluminum alloy 44200 was friction welded to Al/Al2O3 composite. In addition, the following exam were used: optical microscopy, microhardness measurements and also tensile strength for all joints produced by friction welding. All of studies were performed to evaluate the quality of bonding aluminum alloy with metal matrix composite reinforced ceramic phase of Al/Al2O3.

The aim of the work presented in the article was to clarify controversial comments about anti-corrosion and mechanical properties of graphene coatings, deposited on copper substrates. It was designed special experimental cycle comprising: preparation of graphene forms and copper, the observation of layers Cu / GO (rGO) after the thermal reduction processes and oxidative test in air at 150°C temperature and 350 h in time. The resulting coatings and graphene layers were subjected to tribological test for hardness. The observed differences in the continuity of the coverage copper surface by graphene forms, allowed to understand the macroscopic effect of increased hardness and wear resistance layers rGO/Cu.