Abstract: The present invention describes an effective grain refining practice for aluminum foundry alloys. The method described herein relies on the control of the Titanium level of the alloy to be grain refined and the addition of boron once it is melted. Boron addition can be made via Al—B master alloys as well as with boron compounds such as KBF4 salt. The boron added into the melt dissolves first and then forms the AlB2 particles that act as potent substrates for the nucleation of aluminum once solidification process starts. The Ti concentration of the alloy must be controlled below 100 ppm for this method to offer effective grain refinement. The boron becomes ineffective when the Ti concentration in the alloy is higher.

Abstract: The present invention describes an effective grain refining practice for aluminium foundry alloys. The method described herein relies on the control of the Titanium level of the alloy to be grain refined and the addition of boron once it is melted. Boron addition can be made via Al—B master alloys as well as with boron compounds such as KBF4 salt. The boron added into the melt dissolves first and then forms the AlB2 particles that act as potent substrates for the nucleation of aluminium once solidification process starts. The Ti concentration of the alloy must be controlled below 100 ppm for this method to offer effective grain refinement. The boron becomes ineffective when the Ti concentration in the alloy is higher.

Abstract: Thermal fatigue is the predominant mechanism that limits the service life of dies in semi-solid forming of steels since the feedstock to be shaped has a paste-like character. A novel alloy, more resistant to these conditions than any other alloy, has been developed. Eutectic carbides in Stellite alloys are replaced in this novel alloy with molybdenum-rich intermetallic compound particles between dendrites. This novel alloy offers at least 3 times longer service life with respect to Stellite 6 alloy that has been tested under conditions that mimic the steel semi-solid forming process and has been identified as the most suitable. The exceptional performance of the novel alloy is attributed to its outstanding resistance to oxidation and to softening at elevated temperatures and to its cobalt based matrix free from the hard and brittle carbides that have a negative impact on crack growth process.

Abstract: A process is provided for producing an aluminium-titanium-boron grain refining master alloy containing titanium boride and titanium aluminide particles, the process comprising melting aluminium in a silicon carbide crucible in a medium frequency induction or an electric resistance furnace, adding to the melt at a temperature between 750 degrees Celsius and 900 degrees Celsius, KBF4 and K2TiF6 salts, pre-mixed in proportions to obtain a Ti/B ratio of 5 in the melt, gently mixing the salt mixture with the melt without introducing any stirring, transferring the molten alloy to an electric resistance furnace maintained at 800 degrees Celsius, decanting the K—Al—F salt, the by-product of the salt reaction, thoroughly stirring the molten alloy in the SiC crucible with graphite rods before finally casting the molten alloy into cylindrical molds in the form of billets and finally extruding the billet into 9.5 mm rods.

Abstract: A process is provided for producing an aluminium-titanium-boron grain refining master alloy containing titanium boride and titanium aluminide particles, the process comprising melting aluminium in a silicon carbide crucible in a medium frequency induction or an electric resistance furnace, adding to the melt at a temperature between 750 degrees Celcius and 900 degress Celcius, KBF4 and K2TiF6 salts, pre-mixed in proportions to obtain a Ti/B ratio of 5 in the melt, gently mixing the salt mixture with the melt without introducing any stirring, transferring the molten alloy to an electric resistance furnace maintained at 800 degress Celcius, decanting the KAlF4 salt, the by-product of the salt reaction, stirring thoroughly the molten alloy in the SiC crucible with graphite rods before finally casting the molten alloy into cylindirical molds in the form of billets and finally extruding the billet into 9.5 mm rods.