Aluminum based alloys equally exhibit low density and good mechanical properties. Reinforcement of such alloys with Mg2Si can lead to additional improvements in the mechanical properties, especially in thermal resistance, together with a reduction in density. Only a low Mg2Si- content can be reached in aluminium alloys using a common process. A fine distribution and high Mg2Si-content (> 15 mass-% Mg2Si) can be achieved by spray forming.Due to its higher solidification rate the formation of undesired phase morphologies is suppressed by this production technique. Aluminum alloys with Mg2Si-contents of 22-34 mass-% were successfully spray formed and were subsequently extruded and heat treated. Additional alloying with 1.8 mass-% copper leads to a further increase in strength by metastable Al-Cu-phases. The microstructure, density and mechanical properties of these new light-weight aluminum alloys have been investigated. The size of the primary Mg2Si-particles in the alloys was not influenced by extrusion or heat treatment while changes in the other phases were observed. An increase in Mg2Si-content reduces the density to below 2.5 g/cm(3) while improving the mechanical properties. During tensile tests at elevated temperatures the material exhibits good thermomechanical resistance. The Mg2Si particle size, obtained by variations in the spray forming prozess, had a significant influence on the mechanical properties. Applications for the new light-weight aluminum alloys can be expected wherever a reduced density together with high hot yield strength would lead to a more compact design in high temperature environments, such as in combustion engines.

Kurzfassung Legierungen auf Aluminiumbasis zeichnen sich durch eine geringe Dichte bei gleichzeitig guten mechanischen Eigenschaften aus. Die Verstärkung von Aluminiumlegierungen durch Mg2Si kann zu einer weiteren Verbesserung der Eigenschaften, insbesondere der Warmfestigkeit, bei gleichzeitiger Dichtereduzierung beitragen. Durch gängige Gießprozesse lassen sich lediglich geringe Mengen Mg2Si in die Aluminiummatrix einbringen. Das Verfahren des Sprühkompaktierens bietet die Möglichkeit, eine feine Verteilung der Mg2Si-Partikel im Gefüge auch für große Mengen (> 15 Ma.-% Mg2Si) zu erzielen. Eine Vergröberung der Partikel wird hierbei durch hohe Abkühlraten unterdrückt. Aluminiumlegierungen mit Mg2Si-Gehalten von 22-34 Ma.-% konnten mittels Sprühkompaktieren erfolgreich hergestellt werden. Sie wurden anschließend stranggepresst und wärmebehandelt. Allen Legierungen wurde ca. 1,8 Ma.-% Kupfer beigegeben, um eine zusätzliche Steigerung der Festigkeit durch metastabile Al-Cu-Ausscheidungen zu erreichen. Die Werkstoffe wurden zur Beurteilung der Ausscheidungsverteilung metallografisch untersucht. Es konnte gezeigt werden, dass für die untersuchten Legierungen die Mg2Si-Partikelgröße sowohl während des Umformens als auch während der Wärmebehandlung nahezu unbeeinflusst bleibt. Die Form und Verteilung der weiteren Phasen hingegen hängt wesentlich vom Wärmebehandlungszustand ab. Mittels Dichte- und Härtemessungen konnte die Gewichtsreduzierung bei gleichzeitiger Verbesserung der mechanischen Eigenschaften nachgewiesen werden. Die Warmfestigkeit der Werkstoffe wurde anhand von Zugversuchen bei erhöhter Temperatur bestimmt. Ein signifikanter Einfluss der durch Variation der Prozessführung beim Sprühkompaktieren eingestellten Mg2Si-Partikelgröße auf die mechanischen Eigenschaften konnte ausgemacht werden. Anwendungen für diese neuartigen Aluminiumlegierungen sind in Bereichen zu erwarten, in denen geringe Dichten in Verbindung mit hoher Warmfestigkeit gefordert sind, z. B. in Verbrennungsmaschinen. ▪

高性能过共晶铝合金喷射沉积缸套是缸套的目前工艺水平.这种缸套通常借助压铸镶铸于机体,该部件有助于降低燃油耗或提高功率.重量轻、排放低、整个使用期内几乎无磨损是这种工作表面工艺的几个优点.

Aluminum alloys with high Mg2Si-content (>10 %) offer the possibility of a significant decrease in density and an increase in stiffness at the same time. But these alloys can hardly be produced in casting processes, due to an oxidation and a generation of pores by hydrogen solubility of the melt. Furthermore, the usual solidification rate is not sufficient for a fine microstructure morphology. A fine distribution of Mg2Si is possible by spray forming, where a coarsening of the particles can be avoided due to a higher solidification rate. Different aluminum alloys with high Mg2Si-content (>10 %) have successfully been produced by spray forming, extrusion and age hardening. Mg-excess as well as Si-excess has been investigated. An additional alloying with copper leads to a further increase in strength by the precipitation sequence of Al2Cu. The new light-weight aluminum alloys have been investigated regarding age hardening, physical and mechanical properties. Densities of 2.5-2.6 g/cm3 and Young´s modulus of approx. 80,000 MPa have been found. Microstructures were dense, homogeneous and of fine morphology. The yield strength of these alloys reached values of approx. 400 MPa after artificial aging, whereby only a slight decrease for the hot yield strength was observed up to a temperature of 200 °C. Applications of the new light-weight aluminum alloys can be expected where a reduced density together with a high hot yield strength would lead to a more compact design in high temperature environments, e.g. in combustion engines.

Most recently several new types of aluminum alloys were developed at the R&D Centre of PEAK Werkstoff GmbH, located in Velbert, near Düsseldorf. In any case, these new alloys make use of the high solidification velocity during spray forming. This leads to interesting microstructure with a high volume content of primary phases. These primary phases which can be pure Si-crystals or intermetallic phases like Mg2Si, Al3Fe are responsible for the good strength also at elevated temperatures. In the case of Mg2Si volume fraction of up to 25% could be reached. Due to the low density of the magnesium silicide, the overall density of this alloy has been reduced down to 2,5 g/ccm, but with comparable strength to normal 2xxx series alloys. After spray forming a subsequent extrusion is mandatory to close residual porosity resulting from the atomising process. In some cases a additional heat treatment is applied to optimise properties according to the application. This presentation will show you the “making of” such alloys, their properties as well as present and potential applications.

The invention relates to an alloy based on aluminum, at least comprising, in weight percent: between about 15% and about 30% silicon and at least 1% nickel, further wherein at least one of the two, iron, or titanium is present and the sum of proportions of nickel, iron and titanium is at least 3%, and a molded part made from this alloy.

A process is disclosed for manufacturing thin-walled pipes made of a heat- and wear-resistant aluminium-based material. A billet or tube blank made of a hypereutectic AlSi material is produced, optionally overaged by an annealing process, then extruded into a thick-walled pipe. The thus produced pipe is hot shaped into a thin-walled pipe. This process is particularly suitable to manufacture light metal cylinder liners for internal combustion engines, since the thus manufactured cylinder liners have the required properties regarding wear-resistance, heat-resistance and lowered pollutant emissions.