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Ion bonding stainless steel manual#

A kind of contaminant soup forms on the top (see diagram above). This evolution of the surface from a clean, high energy surface to a contaminated, low energy surface continues as long as the surface remains exposed.

And with each molecular group that attaches itself, you lose a reactive site and you lose some of that chemical potential. You also get water vapor in the form of hydroxyl groups that attach themselves to these reactive sites. Within milliseconds oxygen starts attaching itself to these reactive sites created by fracturing the bonds on the first few molecular layers. To better understand what abrasion and other surface preparation methods are doing look at the diagram below: When you abrade a surface you cleave through the bulk material and fracture molecular bonds. The chemistry of every surface needs to be understood and controlled in order to have the maximum effectiveness in creating bondable surfaces. Even if the intended impact is to merely rough up the surface, chemical bonds are being broken and chemicals are being added to that surface that are coming into contact with the adhesive or coating. Over time, surfaces can degrade just by being exposed to a production environment or even the materials the parts are stored in during their time on the shelf.Įvery surface preparation method changes the chemical nature of the material surface. The effect of aging on a surface is more than just collecting dust that needs to be blown off. Here’s an article we recently wrote on that exact subject. Aging is a major factor to consider throughout the adhesion process because the effects of time on a surface can be monumental. The property of the surface that changes while in storage is the chemical characteristic of the surface. So, what makes the difference? Surface Chemistry is the Difference But the roughness of the surface would be unchanged. It’s well understood that this part will not be able to be bonded to or coated in the same way that a freshly prepared part would. Here’s a common scenario in a production facility: Let’s say we abrade a part, rinse it with the proper solution and let it sit for six months in storage. Finally, even if abrasion is the only surface treatment process used, it frequently will remove at least some of any contaminationĪnd this isn’t exactly news to manufacturers.Plastics and other formed or cast materials need to be completely cleaned of mold release and other oils before abrasion so those contaminants aren’t being ground into the surface of the material.

Stainless steel is often cleaned with a hydrochloric acid/hydrogen peroxide/formalin/water combination.

Some metals are dipped in a phosphoric acid solution.

When most surface are abraded they are also typically cleaned in some other way as well. What’s more is, good adhesion can be indirectly attributed to surface roughness when this isn’t necessarily the case. The fatal flaw in this assumption is that adhesion failures and issues still exist in processes that only rough surfaces up in order to create better adhesion. If sanding a surface makes grooves and flattens out peaks in the tiny topography of the surface, then the going theory says that there are more places for the adhesive to hold on to which averages out to better adhesion overall. The idea behind roughing up a surface in order to promote adhesion comes back to the idea of creating “more” surface, or expanding the “surface profile” upon which to adhere. The question becomes, how much does this matter? Is the roughness of the surface the end all be all of surface characteristics in creating predictable adhesion? If so, why is it that we can make tremendous adhesive bonds to surfaces as smooth as polished metal, glass, or an atomically smooth silicon wafer? The Going Theory of Surfaces You can often see or feel the difference made.

Ion bonding stainless steel manual#

Abrading, media blasting, chemical etching, laser etching and other manual forms of surface manipulation used to prepare or clean a surface changes the roughness of the material. The instructions included with most adhesives frequently state “.roughen the surface thoroughly prior to applying the adhesive”. Preparing material surfaces for assembly, coating, painting or adhesive bonding typically includes steps that undoubtedly alter the landscape of that surface.

When the subject of material surfaces comes up among manufacturing engineers the discussion usually centers on the physical attributes of that surface the surface topography or morphology, or more simply - the surface roughness.