Cast iron material with lamellar graphite for cylinder crankcases of motor vehicles, comprises an aluminum alloy and a basic matrix, which is formed from particle-like hard inclusions with non-metallic character and forms lamellar mixture

摘要

The cast iron material with lamellar graphite for cylinder crankcases, comprises an aluminum alloy and a basic matrix, which is formed from particle-like hard inclusions with non-metallic character and forms a lamellar mixture from iron-aluminum-carbide with ferrite and/or from iron carbide and ferrite. The hard inclusions have a hardness of 1000 HV (Vickers hardness), and contain manganese, aluminum, sulfur and/or magnesium. Magnesium sulfide and magnesium oxide are used as nucleating agents for adsorption of manganese and aluminum. The hard inclusions have round or rounded corners or edges. The cast iron material with lamellar graphite for cylinder crankcases, comprises an aluminum alloy and a basic matrix, which is formed from particle-like hard inclusions with non-metallic character and forms a lamellar mixture from iron-aluminum-carbide with ferrite and/or from iron carbide and ferrite. The hard inclusions have a hardness of 1000 HV (Vickers hardness), and contain manganese, aluminum, sulfur and/or magnesium. Magnesium sulfide and magnesium oxide are used as nucleating agents for adsorption of manganese and aluminum. The hard inclusions have round or rounded corners or edges. The structure of the cast iron material is adjusted in such a way that a gradient is present in the lamellar spacing of the mixture from iron aluminum carbide with ferrite and/or iron carbide and ferrite, such that the lamellar spacing of the mixture is smaller in the lamellar graphite and the lamellar spacing is larger with increased removal of graphite surface. The lamellar spacing at graphite surface is 1000 nm and decreases to 200 nm. The number to hard particles is 50-70 particles per cm 3. An interval of 20-2000 ppb is provided for the sulfur activity and an interval of 20-2000 ppb is provided for the oxygen activity and the addition of aluminum and sulfur takes place according to the adherence to the interval and/or intervals. The cast iron material contains carbon (3.2-4 wt.%), aluminum (5-6 wt.%), silicon (1-3 wt.%), copper (0.6-0.8 wt.%), tin (0-0.1 wt.%), magnesium (0.002-0.005 wt.%), manganese (0.7-2 wt.%), sulfur (.05-0.15 wt.%), and iron with impurities (less than 0.5). An independent claim is included for a cylinder crankcase.