Modern Machine Shop and MoldMaking Technology present ADDITIVE MANUFACTURING, a quarterly supplement reporting on the use of additive processes to manufacture functional parts. More at additivemanufacturinginsight.com.
Issue link: https://am.epubxp.com/i/104365
is to use a hard, resistant material such as H13 tool steel for the surface of the mold and a highly conductive material such as a copper alloy for most of the remainder of the mold. Optomec and POM—both using LENS technology from Sandia Labs—have successfully used additive manufacturing to directly produce molds and dies with copper cores. Ultrasonic Consolidation, commercialized by Solidica, is now being promoted for rapid tooling by Fabrisonic under the name ultrasonic additive manufacturing (UAM). The process can produce molds out of aluminum, copper and steel that can be used for die casting, investment casting and vacuum forming. UAM can produce complicated conformal cooling passages and also bond dissimilar metals, allowing for molds with multiple materials. Spray metal technologies, such as those from RSP Tooling and Ford Motor Co., also have demonstrated significant tool life improvements with functionally graded materials. Jigs and Fixtures AM has also been used for several other types of tooling, including jigs, fixtures, templates, drill guides and other devices. Where this tooling involves complex shapes or multi-axis hole patterns, AM can provide significant benefits. Shapes are digitally and accurately produced to match for registration. The number of copies of fixtures or jigs required on an assembly line often is quite low, but Conformal and conventional cooling channels in a mold for cups. Courtesy of EOS. after producing the first iteration of a tool, successive versions can be produced quickly as needed. Other tooling suitable to be made this way includes conformal press tools, drilling and trimming guides, wire harness check gages and holding tools for quality control inspection. Future Opportunities Although many niche solutions exist, an advance is needed in the area low-volume production. For quantities between 100 and 500 units (depending on size and complexity), it can be difficult to determine the best AM or tooling-based process. One reason for this is that requirements change daily in the shop. An engineer may need to tweak a shape or geometric feature, or a customer may need 10 units one day and 100 the next, followed by 50 of a different design permutation. Because of their thermoplastic material outputs, FDM and SLS, coupled with post-processing innovations, will likely make an impact in this area. Also, metal AM companies like EOS and ExOne can improve machine tools and processes to deliver fast, accurate and smooth parts directly from the machine. Design limits have not been removed by AM, but they have changed. The feasibility of conformal cooling is an example of this change. Now that the new constraints have been defined and awareness of the change is advancing, increasingly innovative thermal management solutions are likely to be developed. An important consideration in assessing why AM hasn't made a bigger impact to date on tool making is that real, value-added change takes a long time to implement. Even as effective rapid tooling methods evolve, a company that is already knowledgeable and efficient in its current methods will typically be reluctant to change. The most effective driver for change can be competition. When a few trailblazers prove the value of an emerging process, competitors often follow. Contributor: Michael Siemer of IMDS has 17 years of product development and AM experience. In 2003, he founded Mydea Technologies, a Kinkos-like AM service bureau later acquired by IMDS. Some of this article is excerpted from the rapid tooling section of Wohlers Report 2012, which he coauthored. February 2013 — 7