One of the highest potential cost factors of an iron, steel or bronze foundry is casting rejects and casting cleanup cost. Sand, binder system, and sand additive selection can most readily control this cost.
SphereOX is the only spherical foundry sand additive developed and produced for the foundry industry. It is a synthetic engineered sand additive consistently more pure than other sand additives or natural oxides. When used as an additive in foundry cores/molds SphereOX significantly reduces surface defects and improves the quality of the castings. It has excellent flow properties and requires less resin to achieve the required mold core bond strength.
Digger tooth - no SpherOX
Digger tooth 2.0% SphereOx
Digger tooth - 2.5% SphereOx
Digger tooth - 3.5% SphereOx
Digger tooth - 4.5% SphereOx
Engine block cores250
Engine Block 250
Cores made with SphereOX
SphereOx reduces defects in tough castings.
Before SphereOx, paper pulp grinding plate has many defects.
Paper pulp grinding plate comes out nearly flawless with SphereOx.
Spend less time cleaning up defects by using SphereOx.
Impeller - No SphereOx
Impeller - with Sphereox
Foundries that use SphereOX have reported increased productivity by eliminating cleaning room work through elimination of persistent veining, penetration, and pin-hole problems. Foundries have reported better casting surface finish that results in a casting of higher value.
The addition of 8% SphereOX to the core sand system made it possible to cast threads in a Wear Resistant Iron Casting ( Wear Hammer) with no casting defects!
You can achieve similar savings in machining and cleaning room costs by using SphereOX for iron, steel or bronze castings.
SphereOX’s unique manufacturing method results in a predominantly spherical shape of unique physical and chemical characteristics. SphereOX is the only predominantly spherical, extremely pure iron oxide. SphereOX contains higher FE content than any other commercially available oxide product. It is a finely balanced, critically sized, ferrous product predominantly consisting of Fe3O4.
There are no binders, glues, or other ingredients added to SphereOX that would increase surface area or add hydrocarbons or any other volatiles that could create gas during casting. In fact, to our knowledge, only SphereOX produces a gain on ignition (GOI) of approximately 10% when heated which proves its capability as a gas scavenger. Most common defects are caused by parting of molds (veining), gas entrapment (pin-holes), iron or steel penetration (burn-in and burn-on), lustrous carbon (excessive carbonaceous material) and mold expansion (critical dimension). SphereOX eliminates these problems.
No-bake resin systems that hold the mold together produce gases. Resins are formulated to provide greater adhesive strength than cohesive strength. The stronger the mold the less chance of parting. Minimizing the quantity of high cost resin but obtaining full coverage one molecule thick is the objective. Round sand and round grain iron oxide maximizes the possibility of obtaining that objective because a round shape minimizes surface area. Foundry technicians are encouraged to inspect SphereOX under a microscope and compare it to competitive iron oxides or any other proprietary foundry sand additive. Notice the significant difference in shape, uniformity of size, and lack of dust when comparing it with any other additive. It is suggested that the foundry perform tensile strength comparisons of SphereOX against other additives using varying amounts of additive and reducing amounts of binder system. Typically, reductions of 10% or more binder are possible at comparable or higher mold tensile strengths when using SphereOX compared to other additives. Reducing binder reduces the quantity of generated gas and generated VOC’s and HAP’s during casting!!!
SphereOX’s spherical shape also allows the passage of harmful gases from the metal/mold interface. Competitive products which are dusty, absorbent, granular, and flake-shaped tend to act as a physical barrier at the mold/metal interface, plugging the mold and preventing beneficial mold gas permeability.
Mold dimension stability is critical for castings. SphereOX has a much higher specific gravity and higher thermal conductivity than sand resulting in more rapid chilling at the mold/metal interface. Rapid chilling assures casting dimension stability. In some cases, SphereOX can be used with silica sand to replace zircon sand. Usually higher percentages of oxide are required such as 5 to 8% by weight.
Because SphereOx has no hydrogen ions, it is not measured via ph, but it is compatible with most resins and binder systems. It is available in multiple size ranges, but generally as size 75 AFS.
No other additive provides the flowability that is achieved with SphereOX. Conventional additives and iron oxides tends to bridge and flow unevenly in feeder systems resulting in non-uniform distribution in the batch. Non-uniform distribution of additives causes large variations in mold capabilities that may cause casting failures or defects. Typically foundries use extra iron oxide to compensate for poor mixing which only results in higher cost and more variability in the final product.
Naturally occurring magnetite or hematite may contain high percentages of other non-desirable elements. Hematite (Fe2O3), red iron oxide, may be good as a coloring agent or a source of oxygen, but hematite iron oxide is not as efficient as SphereOX because the red iron oxide absorbs resin and lowers tensile strength while not providing much chill. Proprietary additives and competitive grades of black iron oxide usually contain heavy metals, carbonaceous material, and other fillers which also increase resin comsumtion. Engineered additives can also contain volatiles, which could convert into gases during casting that cause veining, pin-holes and lustrous carbon defects - the defects that you are trying to reduce!
It is interesting to note that before using SphereOX the carbon content is .05%, but after casting the carbon content of SphereOX increased to .7% to .9%. This indicates that scavenging of carbon takes place and helps to explain how SphereOX cures lustrous carbon defects.
Mold tensile strength is critical to quality castings. SphereOX provides higher mold strength than any other additive. This not only reduces veining but also flaking or spalling. Typically additions of 2% to 5% are sufficient to prevent flaking, veining, pinholes, or spalling. Comparison of tensile strength and trials using SphereOX at various additive levels is recommended.
Using SphereOX can also allow for lower pouring temperatures which decreases overall energy cost. Some foundries will pour metal at a higher temperature to reduce the chance of gas entrapment in the casting. Because SphereOX absorbs the gases, it is possible to pour at lower temperatures. For instance, a casting poured at 1425c (2597f) may only have to be poured at 1343c (2450f). This also helps to provide a much smoother surface finish (no burn-in or penetration) even without coating in some cases.
As many of our satisfied customers suggest, “Ask your foundry workers.” Foundry workers love SphereOX. It is virtually dust free, non-staining and thus provides a much cleaner work environment.
Chesapeake Specialty Products, Inc. has technical specialists and an established organization of qualified distributors that specialize in foundry systems.