A use case for silicon carbide riser tubes cast close to final shape for aluminum low pressure die casting.
A riser tube stands in molten aluminum for every shot.
Its shape and its surface decide how long it lasts
This use case covers riser tubes for aluminum low pressure die casting made from OXYTRON 015XDII, the oxide bonded silicon carbide Blasch introduced in August 2020. The grade combines wear and corrosion resistance with thermal shock resistance and does not wet in molten aluminum, and the Blasch process casts the tube with its seats and transitions in one piece.
In low pressure die casting, the riser tube connects the holding furnace to the die. Pressure on the melt pushes aluminum up through the tube into the cavity, and when the pressure drops, the metal falls back. The lower end sits in the melt for the whole campaign. The upper end cycles between hot metal and air with every casting.
Tubes fail by erosion, by aluminum and oxide sticking to the bore, by cracking from thermal shock, and at the seat where they meet the die or the furnace lid. Each change stops the casting cell.
A riser tube cracks where its geometry is weakest, so a grade with good thermal shock resistance only pays off when the tube can be cast with the transitions the casting cell needs.
OXYTRON 015XDII is the latest generation of Blasch oxide bonded silicon carbide. It was developed for wear and corrosion resistance in non-ferrous metal handling, keeps the thermal shock resistance of silicon carbide and is non-wetting to aluminum, so less metal and oxide build up in the bore.
Blasch casts riser tubes and bushings close to final shape. Flanges, steps and tapers are part of the casting, so the tube does not need machining that could leave stress in the ceramic. Besides OXYTRON 015XDII, Blasch makes riser tubes in aluminum titanate and fused silica, and the grade is chosen for the alloy, the cycle and the furnace.
Riser tubes and bushings for low pressure die casting in three ceramic grades.
The oxide bonded silicon carbide grade behind this use case.
Rotary degassers, porous plugs, ladles and riser tubes for aluminum.
No. It is a solid oxide bonded silicon carbide. The whole tube is cast from it, there is no surface layer that can wear through.
Blasch makes riser tubes in aluminum titanate, silicon carbide and fused silica. The choice depends on the alloy, the cycle time and how the tube is held.
No. The dimensions of the tube you use today, the furnace and the alloy are enough to start.
Tell us the alloy, the tube dimensions and how many shots a tube lasts today. A Blasch engineer suggests a grade and a shape for your cell.
