More affordable additive manufacturing could revolutionize the metal casting industry, according to study findings Lippert Components presented to the world’s largest society of industrial engineers.
Chitralekha Beniwal, a business systems analyst for the Elkhart-based recreational vehicle parts manufacturer, presented the findings at the 2017 Institute of Industrial and Systems Engineering conference in Orlando, Fla., according to a July company statement.
The findings were detailed in the conference publication, “Integration of Binder Jet Additive Manufacturing Technology into Metal Casting Industry,” which she presented as a continuation of her master’s degree research at Penn State University. She collaborated on the study with Paul Lynch at Penn State and Joseph Wilck IV at College of William & Mary.
The study involved reviewing conventional sand casting and additive manufacturing advantages and drawbacks, comparing their current costs and conducting a survey of 19 foundries in and around Pennsylvania to see where they stand with additive manufacturing.
Based on the current cost of binder jet additive manufacturing equipment available to the industry, “we prepared a cost model, and then there were factors you could plug in to find out how it compares with the traditional method,” Beniwal said.
A sand mold for a conventional sand casting is made by compacting sand around a pattern, which is shaped exactly like the component that eventually will be made by pouring molten metal into the mold and then breaking it off once the metal has cooled. Destructible cores often are used with the mold to create precisely shaped cavities within it.
Binder jetting additive manufacturing lays down a liquid binder between layers of powder and particles such as sand precisely to build a patternless mold through an additive process, layer upon layer.
Five of the foundries in the survey said they were using binder jet printed sand molds and cores supplied to them by a third party. One of the foundries had access to a binder jet printer through a manufacturing parent company and one of them bought a binder jet printer a year after the survey.
Survey participants familiar with the technology identified tooling elimination and lead time reduction as its biggest advantages, followed by its ability to produce better and more complex designs.
Molds involving complex geometry - which are very difficult to create through the conventional method - pose no problem for binder jetting additive manufacturing. Design changes can be completed much more easily and quickly through the new technology.
Findings of other research reviewed and summarized in the study showed conventional pattern and core box production can take weeks, and with binder jetting additive manufacturing equipment “you can probably just have it overnight,” Beniwal said.
However, the capital cost of binder jet additive manufacturing equipment was by far the technology’s biggest drawback, followed by insufficient demand for its distinctive capabilities, then the need for specially trained technical staff.
Among foundries that don’t do much work with molds involving complex geometry, “I don’t know who would want to spend $700,000 or $1 million to buy the machine unless there’s demand for it,” Beniwal said.
Theoretical cost curves developed for the study showed even with the current cost of equipment, work requiring design changes can make binder jetting additive manufacturing cheaper than conventional sand casting. Some of the surveyed foundries indicated interest in buying binder jet additive manufacturing equipment if its price came down to $100,000 or less.
“With future work on integrating this technology into foundries and making it more affordable, the binder jet additive manufacturing technology has the potential to revolutionize the whole metal casting industry,” the study said in its conclusions.
Beniwal appreciated the opportunity to share findings of the study and to learn what other researchers were discovering about the adoption of the technology, she said.