Advertising in MoldMaking Technology offers
Issue link: https://mmt.epubxp.com/i/812778
EDM 28 MoldMaking Technology —— MAY 2017 incorrect electrode material can complete the job, but at what cost? To ensure the most effective operation, every- one from the shop owner to the machine operator should receive training on the impact of the electrode material on the EDM process. This is not meant to replace the training by the sinker OEM, but rather to supplement that training and enhance the knowledge of the operator with an added layer of knowledge. Let's review five main factors of electrode material selec- tion that can have an impact on EDM performance and that should serve as a basis for the training you should offer your EDM operators. Machinability. Simply being easy to machine doesn't necessarily make a material the best choice for an electrode. For example, any machinist who has ever machined graph- ite is aware that it cuts very easily. However, the electrode material must also be strong enough to resist damage from handling and the EDM process itself. Strength and small particle size are also impor- tant so that minimal radii and close tolerances can be achieved. Material hardness is also a factor in graphite machining, as the harder electrode materials will be more prone to chip- ping during the machining process. Metal removal rate (MRR). MRR is usually expressed as cubic millimeters per hour or cubic inches per hour, but could just as realistically be expressed as dollars per hour. Achieving an effi- cient MRR is not simply a matter of the right machine settings, it also involves direct energy dissipated in the EDM process. Graphite electrodes are gener- ally much more efficient than metallic electrodes, however metal removal rates vary widely among graphite types. With the proper electrode material/ work metal/application combination, MRR can be maximized. Wear resistance. The four types of wear are volumetric, corner, end and side. Of the four, corner wear appears to be the most important since the contours of the final cut are deter- mined by the electrode's ability to resist the erosion of its corners and edges. It follows that if an electrode Fine surface finish is obtained with a combination of the proper electrode material, good flushing conditions and the appropriate power supply settings. Help keep molded parts clean and free of finger oils • Available in Lint-Free Nylon/Polyester or 100% White Cotton • Comfortable and Stretchable • Men's and Women's Sizes • Can be worn on either hand Item #168495 Electronic Scale (shown) Item #100979 Cotton Glove (shown)