Aluminium Oxide in a Dana-Ridge Wetblast Unit
In this article Dana-Ridge is going to focus on another popular media used in our wetblast machines and is one of the fastest cutting abrasives around. As opposed to glass bead for example, aluminium oxide,or alumina (Al2O3) , is angular/cubic in shape and rather than a scrubbing action on the surface, it has a more of a cutting process. This opens up a whole new set of applications for your Dana-Ridge wetblast unit.
Aluminium oxide is a compound of aluminium and oxygen and is used in many abrasive applications including grinding discs and sandpaper. In fact, it can be found in countless other applications but we will only consider it in the context of wet blasting here.
Being rated at nine on the Mohs hardness scale means it is very hard and tough and when it does break apart, it breaks into new angular shapes to expose a new cutting surface.
Combined with the heat and dust-suppression qualities of the wetblaster, the media becomes an especially safe and cost-effective way to clean components.
Dana-Ridge has seen rooms fill with aluminium oxide dust from dry units when the filters have failed. The Dana-Ridge wetblast unit has eliminated these hazardous situations while providing a superior finish, much to the delight of the customer.
The water in the Dana-Ridge wetblast process means even longer life from the media giving even more benefits.
The results are a matte surface finish and with a range of grades available, you can achieve a nice keyed surface for paint adhesion through to micro-finishes on precision-dimensioned parts.
Like glass bead, the variety of sizes will achieve a variety of results. Additionally, there are different colours, purities, shapes, toughness and hardness.
Brown, white and pink grades are available from Dana-Ridge. Brown is the most common and economical and has an Al2O3 content of approximately 95%. It is not as hard as the white but it is tough. It suits most applications and does an excellent job.
White is also popular with an Al2O3 content of approximately 99%. In industries that are concerned with chemical impurities in the brown oxide, white becomes even more desirable. It has a higher hardness and a slightly lower toughness than the brown and is slightly more efficient in the blast process.
Pink oxide is basically high purity white oxide with chromium oxide (Cr2O3) added during the fusion process and it is this, that gives it the pink colour. Compared with brown and white oxide, it is harder, more aggressive and has better cutting ability. Due to the added process and material used in its creation it is the more expensive of the three types but it has the longest life of the three.
All three will perform very well in a Dana-Ridge wetblast unit and because of the water cushion effect of the process, there is less chance of media impregnation into the part being blasted. This means the impurities in the brown oxide become less of a concern and is yet another advantage of the wet process over the dry.
Dana-Ridge supplies a variety of sizes in 25kg bags with some of the more common sizes below.