Technology bulletin 172

DN Staff

December 4, 1995

8 Min Read
Technology bulletin

Process lowers cost, improves quality of ceramics

Forming high-quality, complex-shaped ceramic parts quickly and cost-effectively has taken a big step forward with a new process called gelcasting. Developed by engineers at the Oak Ridge National Laboratory, the process combines techniques borrowed from traditional methods of producing ceramics with polymer chemistry. The liquid-based mixture, or "slurry," contains ceramic powder, water, and simple molecules (monomers) that combine with other molecules. The slurry is poured into a mold, and a chemical reaction is initiated to form a polymer-water gel that locks the ceramic particles in place. The part is removed from the mold, dried, and then fired to fully develop its strength and other properties. The finished products require little or no additional shaping. Other advantages include: short molding time, greater precision, and minimal defects and warpage of components. FAX Joe Culver at (423) 574-0595.


Inspection technique targets hard-to-test structures

Researchers at Iowa State University have developed an ultrasonic inspection technology that can detect small defects in large, complex industrial parts or even bridges. The GlobalView nondestructive tests can uncover an 0.008-inch flaw in a 1.5-inch steel piston, or a 4-inch crack in a 100-foot bridge girder, according to Sam Wormley, one of the developers. "Any size, shape, or composition of structure can be inspected," Wormley adds. GlobalView transmits a very broad band ultrasonic signal that floods the test object or structure with acoustic energy. GlobalView receivers capture the readings that result when sound is reflected from changes within an object. With conventional ultrasound methods, a complete scan of complex or large parts requires several placements of the transmitter and receiver, or the part has to be rotated during the test. By employing correlation techniques, and since it is not limited by background noise, the program can be made much more sensitive to changes in the part or structure, Wormley explains. FAX Wormley at (515) 294-7771.


Software program gets railcar engineering on track

Netherlands Railways Ltd. and Mechanical Dynamics, Inc. have formed a partnership to develop virtual prototyping software tailored to the needs of the international railcar manufacturing industry. The new software, called ADAMS/RailTM, embeds the design and analytical expertise of NS Materieel, Durth Rail's engineering arm, into Mechanical Dynamics' ADAMS(R) general-purpose mechanical simulation software. With ADAMS/Rail, users can test the stability, derailment safety, clearance, track load, and comfort of new railcar designs--without leaving the comfort of their engineering workstations. "In the past," says Michael Hoffmann, managing director of European operations for Mechanical Dynamics, "the time and expense of physical prototyping made multiple design iterations impractical. Now users can explore hundreds or even thousands of design variations in wheel sets, suspensions, and other assemblies." FAX Mechanical Dynamics' Chris Kochmanski at (313) 994-6418.


Semiconductor giants join forces to develop advanced chips

IBM, Siemens, Toshiba, and Motorola have formed a four-way alliance to develop future generations of highly advanced semiconductor chips, including a 1 gigabit (Gb) dynamic random access memory (DRAM) device. While 4 Mb and 16 Mb DRAMs are currently available, the semiconductor industry is pushing to develop ever more sophisticated memory devices for use in power-hungry systems, such as powerful personal computers and workstations, as well as high-definition digital video, multimedia, and telecommunications systems. A 1 Gb device will have four times the memory capacity of a 256 Mb chip, making possible the storage of 100,000 double-spaced pages of typewritten text on a single chip. FAX IBM's Jim Smith at (914) 892-5334.


System turns out low-cost, high-optical plastic lenses

Rohm Tech, Inc. has introduced a new reaction molding process that can produce very large lenses and refractors with optical clarity approaching that of glass. Use of Rohagum(R) M286 polymer with a methylmethacrylate (MMA) liquid monomer forms the basis for optical items that cannot be produced economically in glass because of size or special design considerations, according to Rohm Tech's Lothar Kruska. The partially polymerized system eliminates problems of heat and shrinkage associated with the conversion of monomeric MMAs, Kruska explains. In the process, a monomer containing the liquid MMA and the Rohagum M286--a high-purity, polymer based on polymethylmethacrylate in white powder form--are combined with a catalyst. The resultant paste is transferred to a mold for curing in an autoclave. FAX (617) 322-0358.


Friction material improves stopping performance of vehicles

Carlisle Motion Control Industries, Inc., Bloomington, IN, has introduced a material for wet brakes used on heavy-duty, off-highway trucks and front-end loaders. For the brake products, the company uses a bonding technology developed in its Industrial Friction Div. to provide a bond between the paper and the carrier disc that it claims is stronger than conventional methods. To prove its case, Carlisle conducted several tests using a Caterpillar 777 haulage truck. The material easily passed the stopping distance requirements outlined in SAE J1473, ISO 3450, Alberta Canada Mine Safety Regulations, and the British Columbia Health, Safety, and Reclamation Code. The material also provides superior speed sensitivity, says Carlisle's Mark Wilson. FAX Wilson at (812) 336-3985.


Technology enhances efficiency and safety of foam products

A new process technology developed by The Dow Chemical Co. should provide fabricators and end-users of polyethylene foam products with excellent handling efficiency and safety. Called RapidRelease, the process incorporates a patented isobutane blowing agent and an accelerated curing system for Dow's EthafoamTM polyethylene foam products. "Our technology reduces the level of residual blowing agent in Ethafoam plank and sheet products to trace amounts, which do not produce a flammable concentration of blowing agents," explains Mark Weick, research and development manager for Dow Plastics. "Customers also should notice enhanced surface quality and smoothness," Weick says. Products made from the process will no longer require special shipping, handling, storage, and fabrication considerations needed for conventional foam products, Weick adds. FAX Glendorah Lawrence at (517) 638-9925.


Multi-company corporation focuses on 'agile' manufacturing

The Ben Franklin Technology Center at Lehigh University, Bethlehem, PA, has announced the formation of Agile Web, Inc. The unique corporation consists of 19 small- to medium-sized companies in eastern Pennsylvania. The purpose: "to provide a new form of integrated supplier chain that applies the techniques of agility for fast-response product design and manufacturing." Web member companies, with combined revenues of $250 million, have a diversity of capabilities. They include: manufacture of electronics and mechanical assembly of circuit boards, electro-mechanical equipment, precision machining and fabricating, custom die castings, complex wire assemblies, custom printed circuit boards, communications equipment, precision sheet-metal stampings, and custom finishes, such as powder metallization and polishing. FAX Ted Nickel at (610) 861-5918.


Acoustic imaging verifies Space Shuttle's ceramic bearings

The metal-alloy bearings in the Space Shuttle's main-engine, liquid-oxygen turbo pump showed signs of excessive wear. NASA planned a switch to silicon nitride bearing balls--if testing showed the balls were free of surface and near-surface cracks. A two-part acoustic imaging process, developed by Sonoscan, Inc., Bensenville, IL, provided the answer. Reflection-mode acoustic imaging, adapted from that used for plastic integrated-circuit packages, imaged for minuscule cracks in a ball down to the critical 0.03-inch depth. Next, acoustic surface waves, which follow the ceramic surface, intercepted the surface cracks, for which, Sonoscan claims, there is no acceptable optical inspection. The inspection took place with the ball mounted on an arm that rotates while swinging slowing through a 90-degree arc, ensuring coverage of half the ball. The ball was then removed and remounted to complete the imaging. The silicon-nitride bearing passed the test. FAX Steven Martell at (708) 766-4603.


Plastics firms to jointly research auto-body panels

The auto industry has indicated increased need to reduce the weight of passenger cars and the time it takes to get products to market. In response to these demands, BASF and GE Plastics have announced they will jointly develop high-performance engineering thermoplastic resins and processing techniques for exterior body panels. "By working together, it will be possible to achieve considerable time and costs savings, while providing the car manufacturers and their customers with a broader choice of solutions," says Diane Actman, marketing representative for BASF Corp. Plastic Materials. Also to be addressed: recycling of such plastic components. Upon completion of the joint research and development, the parties will make, market, and sell the developed materials independently. FAX Actman at (201) 426-3912.


Design contest will send winner to 1996 Summer Olympics

Have you designed an unusual application for magnetic separation, or a vibratory conveying screen, metal detection, or metalworking product? If so, enter Eriez Magnetics' design contest. The Gold Prize winner and a companion will receive airfare, lodging, event tickets, and miscellaneous expenses for the 1996 Summer Olympics. Non-customers are welcome to participate, says Charlie Ingram, the firm's national sales manager. "We encourage contestants to enter applications that they might consider to be routine," he adds. "What an individual considers routine, may be unique to the industry." Four Silver Prize winners will receive $300 worth of travel coupons; Bronze Prize winners will receive $100 in travel coupons. An independent panel of judges will make the awards. Entries must be postmarked prior to midnight December 31, 1995. To receive an entry kit, fax (814) 833-3348.

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