Our capabilities, from design to production
Press to Shape: Typically when referring to ceramic parts that are pressed to shape we are talking about parts that have their net shape coming off of the tooling. The only additional work required by the customer is what is necessary to fit them into your application. Most of our customers add value to our product via metallization or some type of assembly.
Green Machining: Green machining is a term used for machining ceramic material prior to firing. This operation allows us to add additional configurations to a part that has been either dry pressed or iso-pressed that you normally could not obtain by these operations directly. They could be in the form of multiple stepped I.D.’s and O.D.’s as well as notches, cut outs, holes, or some type of shape on the sides of these already formed green parts.
Post Firing Grinding: This refers to grinding after the firing process. Once this material is fired, the only thing harder is diamond. The only way to change the shape or sizes of a fired part is to grind it, ream it, or hone it with some type of impregnated diamond tools (i.e., wheels, reamers, or hones). Ceramic parts can be reamed or ground after firing to achieve a closer tolerance than what can normally be achieved prior to firing.
O.D. / I.D. Grinding: ACCI has several centerless grinders that allow us to hold tighter tolerances on the O.D. We also have an O.D. I.D. grinder that allows us to accomplish this same task on the O.D. and I.D. We have reamed numerous I.D.’s holding tolerances to ± .0005.
Glazing: Glaze is generally considered to be a thin, glassy coating fired onto the surface of a ceramic form normally as a secondary process. Originally glaze was used to help prevent porosity on the outer surface of the fired ceramic body which would in turn prevent the surface from becoming dirty or collecting any metallic substances. With some materials, glaze is still used for the same reasons, but with most of the fully fired aluminas this is not the case. We believe that some of our customers are still using glaze because it has been specified on some type of government drawing or strictly for appearance sake.
Typically we have been supplying all high temperature glazes. These are glazes that will withstand the temperatures necessary for the metallizer to complete their process without deteriorating the glaze. They are normally good to temperatures around the range of 2600°F. A low temperature glaze can be applied to all of the alumina bodies and will normally sustain temperatures in the 1500°F to 1600°F range. As a general rule of thumb, we use the higher temperature glaze to be sure to cover the customer’s maximum temperature range.
Colorization: There are three basic colors that we can produce that will still maintain their color integrity through the high temperature firing; they are purple, blue, and black. These three colors can be produced in ranges actually giving you a spectrum from a light pink to a dark purple and from a light blue to black. The reasons for using colored ceramics vary from needing to be able to recognize a white material such as yarn or thread passing over a purple alumina, or to have a contrast in color for visual purposes, or just for cosmetic reasons, e.g. the black alumina looks very rich when plated with gold.