Tech Front: Researchers to Combine Computing, Materials Science with Maker Movement
Hoping to capitalize on the current wave of interest in additive manufacturing and the maker movement, two professors from the University of Wisconsin-Madison (Madison, WI) and Drexel University (Philadelphia) are aiming to meld recent advances in computing, additive manufacturing and materials sciences into a new discipline dubbed the "informatics of making."
With a new $800,000 grant from the National Science Foundation (Arlington, VA), professors Vadim Shapiro and William Regli are teaming up to try to devise a computational framework that would unite these fields and give manufacturers the building blocks for a rich set of computer tools that would help account for material complexity in new products within a computer model.
"We’re not just talking about computing systems, but specifically computing systems in support of material activities," said Shapiro, the Bernard and Frances M. Weideman professor of mechanical engineering and computer sciences at UW-Madison. "Moving forward requires computational models that know about geometry, materials and physics."
The collaboration calls for Shapiro to add his expertise in geometry, mathematical models and computer models while Regli adds his experience with information systems, knowledge representation and archives. A professor of engineering and computer science at Drexel, Regli has worked in computer science and manufacturing. He contends that computational design tools need to catch up to advances in materials science.
"If I want to design an object that has variable material properties, on a 3D printer, the tools just don’t exist," said Regli, associate dean of research at Drexel’s iSchool, College of Information Science & Technology. "What you’re making is more than a shape; it’s how the shape responds to its physical environment, how it acts under certain forces."
The research will aim to help solve problems encountered when data is exchanged for use in 3D printing. When 3D printer users exchange data on an object they’re trying to print, Shapiro refers to that data as a "dumb" file that transmits only an approximate shape of an object. Shapiro believes the next step is to create models and languages that also include information about the materials, physics and design intent. "It’s almost at the point where you can interchangeably think of materials as bits of information," Shapiro says.
Finding the right abstractions with which to unite principles of design, materials and computing will be the researchers’ main challenge, according to Regli. "We have to figure out how to relate the representations for material and behavior from an engineering standpoint to the computational representations," he says.
If the researchers can accomplish that, it will establish a framework in which manufacturers and engineers can build powerful new tools that harness the potential of three fast-rising scientific disciplines. The scope of the grant is to create an abstract, foundational link between computers and materials and their behaviors, but it aims for profound impact. In their grant proposal, Shapiro and Regli wrote: "If successful, this research should also lead to systematic re-examination of how design and manufacturing are taught and practiced at all levels." ME
Universal Vertical Thread
Grinder Offers Productivity Gains
A new universal vertical thread grinder from Mitsui Seiki USA Inc. (Franklin Lakes, NJ) promises improved accuracy, speed and multifunction capabilities over conventional horizontal grinder designs.
Shown at EMO in Hannover, Germany, the new VGE60A High Precision Universal Vertical Thread Grinder is said to be the world’s first universal vertical thread grinder, offering many important benefits for customers making precision lead screw type parts. The VGE60A grinder recently won the coveted Grand Prize in Japan’s 43rd Machine Design Awards competition sponsored by Japan’s Ministry of Economy, Trade & Industry on July 25.
"There’s been a long trend of switching over from hydraulic to electrical power actuation in a variety of important industries such as automotive, aerospace, and robotics," noted Tom Dolan, Mitsui Seiki USA vice president. "As such, lead and feed screw actuators for electrical power steering, flight control actuators, and automation systems are in increased demand. Along with these market drivers, highly accurate and efficient machining methods for various screws, such as ballscrews, have also been on the rise. Typically, thread grinders have been made the same way for the last 50 years. This new technology changes everything."
The new VGE60A is categorized as a "universal" machine because different grinding operations can be performed, according to the company. In addition to thread grinding, the machine can now perform spline, gear, OD, surface, and edge grinding operations in a single setup, which can save customers significant production time while improving overall part accuracy.
Newly designed features such as an automatic grinding wheel changer, automatic wheel guard, and a CNC-controlled wheel dresser (to accommodate various shaped wheels) vastly improve productivity. Infinitely programmable grinding wheel tilt angles from +45 to -90º provide increased grinding application opportunities. The vertical orientation of the work enhances overall precision. Elimination of workpiece "sag" is the principal contributor to increased precision.
The new vertical configuration requires 33% less floor space than a similar capacity horizontal grinder, and allows for improved human interface with the complete work zone. The VGE60A accommodates a maximum grinding length of 600 mm and an overall shaft size of 80-mm diameter (with the largest diameter wheel) and 700-mm long. The machine is compatible with both oil and water-based coolants.
For more information, contact Mitsui Seiki USA Inc., phone: 201-337-1300, or visit www.mitsuiseiki.com. ME
Nontraditional Processes Handle Difficult Materials,
Cutting-edge waterjet, laser, ultrasonic and electrical processes continue to evolve for new materials, applications and requirements. There are hundreds of SME Technical Papers on the technology progress of 25 processes that are categorized as nontraditional yet are widely used in innovative applications.
Micromachining using a waterjet-guided laser provides excellent, high-precision results in terms of speed and quality at low maintenance cost (paper number TP06PUB121). In TP06PUB82, a hybrid CO2 laser/waterjet is used for cutting glass, silicon and concrete. The waterjet enables the laser beam to cut by thermal stress fracturing, with the debris washed away from the kerf. The thermally shock-induced fracture approach is more effective on glass and silicon than on concrete but has potential energy, speed and accuracy benefits compared with waterjet or laser processes alone. In a related paper (TP08PUB106), a CO2 laser/waterjet cutting system applied to the difficult-to-machine ceramic material polycrystalline cubic boron nitride (PCBN) required more energy than just a laser but produced better cut quality.
Numerous explanations and charts in TP06PUB144 help users identify cost reductions and new revenue sources to maximize the profitability of waterjet cutting. Finding the right balance of quality and throughput is easily achieved by making the most of a 2D laser cutting machine’s parameters by programming and operation (TP12PUB97). For example, choosing air cutting over nitrogen results in faster, less expensive cutting but lower cut quality.
Laser-assisted machining (LAM) and micro-LAM are promising techniques for many materials. As described in TP13PUB5, localized laser heat applied to metal matrix composites (MMCs) reduces strength but increases machinability, leading to rapid material removal, the ability to machine complex shapes and a high-quality surface finish, as well as improved subsurface integrity. TP09PUB30 presents research on pressure and temperature interactions in micro-LAM of semiconductors and ceramics, especially brittle materials such as silicon carbide. Notably, scratch tests at 1 µm/sec show a doubling of the scratch depth, which suggests an approximately 50% reduction of hardness due to thermal softening by laser heating. An approach is presented in TP11PUB54 for laser-induced tempering of hardened steel workpieces, followed by conventional machining at higher material removal rates with ceramic tooling. The hybrid process shows lower cutting forces and tool wear/costs compared with conventional hard turning and, unlike laser-assisted hard turning, achievable material removal rates are not limited by the laser power available.
Rotary ultrasonic machining (RUM) is a hybrid of ultrasonic machining and diamond grinding capable of machining advanced materials such as ceramics, Ti alloys, glass, quartz, structural ceramics and silicon carbide at the macro level. TP09PUB105 explores downscaling of RUM to achieve micromachining of brittle materials. The related paper TP10PUB27 reports on the influence of the main machining parameters—spindle speed, abrasive grit size and vibration amplitude—on material removal rate. Coolants, static loads and tool tip geometries are also studied. TP09PUB53 presents a designed experiment on RUM of stainless steel. Cutting force and torque are among the studied process outputs. ME
TechFront is edited by Senior Editors Patrick Waurzyniak, firstname.lastname@example.org, and Ellen Kehoe, email@example.com.
This article was first published in the November 2013 edition of Manufacturing Engineering magazine. Click here for PDF.
Published Date : 11/1/2013