FOUNDRY ACCESSORIES
Foundry accessories
Products
FOUNDRY ACCESSORIES
Gefond specialises in the supply of aluminium titanate and silicon nitride riser tubes for low pressure furnaces and other applications. High-quality products such as silicon nitride thermocouple protection tubes and titanate aluminium bushings are also part of the supply range. These products are manufactured according to drawings in order to meet various customer requirements.
LOW-PRESSURE RISER PIPES
Gefond specialises in the supply of aluminium titanate and silicon nitride riser tubes for low pressure furnaces and other applications. High-quality products such as silicon nitride thermocouple protection tubes and titanate aluminium bushings are also part of the supply range. These products are manufactured according to drawings in order to meet various customer requirements.
Titanised aluminium riser pipes
Aluminium titanate (Al2Ti05) is a material with very special properties that are particularly suitable for use in foundries. In fact, aluminium titanate (or simply ATI) has an extraordinary ability not to be wetted by molten aluminium, shows no thermal expansion and has excellent thermal shock resistance. For all these reasons, titanate aluminium products last a very long time. Below is a list of parts for the production of which we would recommend ATI:
ATI is not suitable for use with salts or chemical agents containing sodium (Na), as well as for use with aluminum alloys with high content of magnesium (Mg). These two elements (Na and Mg) are highly corrosive and for this reason the life of parts in ATI would be drastically reduced.
Silicon nitride riser pipes
Silicon nitride (Si3N4) is a high-tech material with extremely interesting properties suitable for use in foundries. Silicon nitride (or more simply SN) is not wetted by aluminium, copper, copper alloys, zinc, lead and magnesium. SN shows excellent resistance to corrosion by many alloys and chemicals commonly used in foundries. SN has great strength, low porosity (< 1%) and excellent thermal shock resistance. The thermal conductivity of SN is very high and for this reason it is a particularly suitable material for the production of thermocouple sheaths. Parts made from SN normally have an average life of about a year or more. Below is a list of parts for the production of which we would recommend SN:
Material Comparison TableCERAMIC FILTERS
Ceramic filters are normally used to filter liquid metal in foundries and metallurgical plants. We offer all standard sizes ranging from 7 to 24 inches, but also sizes according to customer requirements. Ceramic sponge filters consist of a complex labyrinth of pores that is created by applying a ceramic mass to polyurethane foam. Our filters are characterised by a homogenous pore structure, and this is undoubtedly our strong point, naturally together with the breadth of our product range. The quality of our products can clearly be verified, especially where temperatures and metal-static pressures are very high. We also offer non-standard customised solutions for liquid metal filtration.
Alumina Ceramic Filters
Spongy Al2O3-based filters, specially designed for the filtration of aluminium and aluminium alloys. For temperatures up to 1350°C. The filter can be placed in a filtration chamber with a filter box system, or inserted into the molten metal inside furnaces, crucibles, riser tubes, etc. They can be filter boxes with either gas or electric heating. They are suitable for very long temperature loads. They are normally used in the standard dimensions shown in the table, with a porosity ranging from 10 to 60 ppi. The choice of filter size depends on a number of considerations: filtration capacity, casting time, and the layout of the filter box. Porosity, on the other hand, is determined by the alloy, the casting temperature, the metal pollution and the type of quality required. For proper functioning, the filter must be adequately pre-heated before casting.
SiC Ceramic Filters
SiC-based sponge filters, specially designed for cast iron and non-ferrous alloy foundries. For temperatures up to 1480°C. They have excellent thermal conductivity, stability and resistance to sudden temperature changes. They can be placed in a filter box or used directly under the metal flow during pouring. They can also be used for continuous filtration of copper alloys.
