How To Make A Mirror Surface Using Sinker EDM

The Sinker EDM machining process uses electrodes that are electronically charged and configured to specific geometry to burn electrode geometry to metal components. The Sinker Electrical Discharge Machining process is a process that is commonly used in the production of molds and dies. It works by having two metal parts submerged in an insulating liquid connected to the current source which is then switched on and off automatically in relation to the parameters that are set by the controller. Electric tension is what is created between the parts when the current is on.

When brought together, the two parts of the metal heats up to a melting point; when the electrical tension is discharged and spark jumps across. Innumerable spark sprays gradually shape the desired form into the metal depending on the electrode shape. The Sinker EDM process is most suitable for those looking to minimize machining risks with accuracy and reliability. One of the major benefits of the process is the ability to produce shapes that are more complex without inducing stress onto the material. It doesn’t cut all the way through the material unless this is a requirement and thus it is a process that has a wider variety of applications including thin walls, blind cavities and cross sections. The efficient technology is great for injection molds and stamping dies and can be used to make the mirror surface too.

How mirror surfaces are done

Mirrors are smooth surfaces that have a shiny dark background that reflect well. Polished metal reflects extremely well and this is something that can be achieved by the sinker EDM. The common raw materials that are used in mirror making include glass, but because it is a poor reflector, it needs a metal layer on its surface to create an even surface with impressive reflection. Plastic substrate works as well as glass and it is commonly used in making mirror surfaces for children’s toys. Injection molding is what is applied to create the desired shape, whether circular or flat, transparent or opaque. Generally, the base materials need to be coated to make a mirror and this is where the sinker EDM comes in handy.

· First, the outline of the blank material is made to suit the application. The final shape desired is what determines the cutting method. The cutting is done before the metal coating takes place.

· Blanks are then placed in optical grinding machines and gritty liquid that is the grinding compound is spread over the blanks as they rub against curved surfaces.

· After the polishing of the surface into a smooth finish, a coating with the desired reflective material is then done. The Sinker EDM is used to heat the metals so they can vaporize and get deposited on the surface. Precision is needed to ensure that the timing and temperature are just right in getting the right thickness and uniformity is achieved in the end.

· Masks and metal stencils can be applied to the surface to create patterns and dielectric coatings can also similarly be applied as reflective layers or protective layers over the metal ones. A number of evaporation steps maybe necessary for multiple layer coating before the mirror is mounted on the base and packed in shock resistant packages.

Post time: 03-25-2017