Voice of the Industry.

QUESTION: If you could direct industry research engineers to develop one shop floor casting technology 'revolution' that could be used in your operation, what would you have them work toward over the next 5 years?

The industry must find a commercial method to lower the gas content of molten aluminum to a level below the solid solubility of hydrogen in solid aluminum and keep it that low until the casting is poured and solidifies. If this could be accomplished, it would eliminate microporosity as a defect, enabling foundries to increase the performance of aluminum castings and increase their market."

--Tom Piwonka, director, Univ. of Alabama, Metal Casting Technology Center, Tuscaloosa, Alabama 

"Foundries need a way to eliminate compressed air from their green sand usage without compromising production time. Vacuum technology is available but awkward and time-consuming. Perhaps molding machine manufacturers could look into incorporating vacuums into their machines as part of the mold cycle. The molds would need to be vacuumed after sand compaction and once again after core/filter setting. Until the day that all green sand foundries run perfect sand with perfect patterns and perfect core-setting, something will have to be done with loose sand. Blowing out molds is not the answer,"

--Andrea Maxinoski, technical services, R.H. Sheppard Foundry Div., Hanover, Pennsylvania 

"I have a friend who recently automated one of his car washes, which reduced the use of several workers to one. As I relate this to my jobbing foundry experience, our bottlenecks are no more apparent than casting finishing, Just as the new car wash process can handle cars of all shapes and sizes, jobbing foundries also have several shapes and sizes to deal with. Small production quantities don't justify capital expenditure such as dedicated finishing equipment or fixtures. It's often difficult to convince our customers to invest in quality pattern equipment that also would improve the finishing process. High-volume foundries, however, can justify the economies of scale that result from this type of dedicated capital expenditure. Along with using current technology more effectively, my direction for research engineers would be to develop a cost-effective, "one-size-fits-all" finishing process technology. Perhaps, one day, buying and making castings can be as quick and pleasant an experience as getting your ca r washed."

--Dwight Barn ha rd, chairman/CEO, Superior Aluminum Castings, Inc., Independence, Missouri 

"The single most revolutionary technological breakthrough would be in the development of a permeable permanent mold for aluminum casting. Most problems associated with permanent mold casting involve mold coating and venting issues. Both of these problems would be alleviated with a permeable permanent mold. Simply stated, design a permanent mold to behave like sand. Technology of materials could make this achievable within the 5-year window."

--Charles Nelson, director of engineering, Morris Bean & Co., Yellow Springs, Ohio 

"The greatest technological challenge facing the cast iron industry is its ability to compete effectively with the lighter-weight metals. Although lightweight iron' is not a realistic 5-year goal, the production of lightweight iron castings is realistic, The achievement will not be accomplished with designed-in porosity nor with lightweight fillers, but rather with the ability to produce sound, thin-wall iron castings (less than 3-mm walls) with excellent physical properties. It is fortunate that the intrinsic physical properties of iron are superior to those of the lighter metals, making it possible for thin-wall iron castings to match or surpass the strength, durability and corrosion requirements of castings currently produced from aluminum and magnesium, However attractive the concept, the reality is that the technological challenges are great. There are four major challenges: the ability to produce desired microstructures in the rapidly cooled iron; the ability to effectively fill a complex mold; the abi lity to produce accurate molds; and the ability to develop these processes without losing the cost advantage of iron,"

--Seymour Katz, president, S. Katz Assoc., West Bloomfield, Michigan

"I would direct engineers involved with lost foam casting to gain a better understanding of the dynamic interaction between liquid aluminum and polystyrene foam, This must be accomplished holistically in that the entire process must be evaluated for effects on this critical interaction, Our goal is to obtain predictability beyond current production so the process can be accurately modeled. To achieve this, the polystyrene/ ceramic-coating interface must be engineered to control foam collapse, liquid plastic morphology and mass transport out of the mold cavity. This may be a surface-controlled process and, as such, must be managed at this interface. Process parameters, including foam, glue, coating, metal, sand and structure, must be controlled to the extent that they influence this interaction. Improved control and understanding will allow the process to realize its full potential. Engineers also must develop the next generation counter-gravity casting process, independent of mold type. Counter-gravity proce sses generally allow for quiescent, controlled mold filling. The next generation process should maintain this benefit, while significantly reducing cost. All castings, regardless of geometry, should separate freely from the sprue, reducing or eliminating cutoff operations, Molds should be created from one thin coating that is easily separated from the castings, eliminating the need for expensive and hazardous cleaning operations. Metal fill profiles should be controllable at all levels of the mold cavity to improve casting quality and yields."

--John Burke, general manager, Metal Casting Technology, Inc., Milford, New Hampshire