Measurements and Standards for Science-Based Manufacturing Program

To remain competitive in the global marketplace, U.S. manufacturing is currently implementing fundamental changes, focused on designing and building complex, highly-customized, high quality goods -- all built speedily to meet the rapidly changing demands of the market. Manufacturers must shorten product development cycles and increase flexibility and speed of production systems and supply networks. And they must do all this while also reducing environmental impacts and energy requirements. These changes require a transformation from manufacturing practices based on human experience towards scientific-based modeling, decision making, and production. This program develops fundamental measurements, standards, and tools to enable U.S. manufacturers to make this transformation. 

A tradition of developing and putting extensive human and organizational experience to use in the creation of new products has taken U.S. manufacturing far -- it remains the largest manufacturing economy in the world. But these methods are not well suited to carry industry to the next level, where a superior ability to make complex, customizable products will put U.S. manufacturers well ahead of their often cheaper competition. NIST helps generate this competitive advantage and stimulate innovation by developing measurements and standards that will be the foundation of a science-based approach to building new goods.

This program draws on decades of NIST expertise working with manufacturing industries. NIST understands the broad needs of fabrication both for established industries such as aerospace or defense and for growth industries such as pharmaceuticals or alternative energy, and so has the ideal background to create standards for science-based manufacturing.

Project researchers have targeted three key barriers to innovation. The first is an insufficient understanding of the science behind key manufacturing processes. Traditional studies of the way a manufacturing process creates a desired shape, for example – such as determining what pressure causes a cutting tool to break or how long it takes for a tool to wear out when cutting a particular material -- take place in highly specialized lab environments. But such studies do not provide enough information on the forces, friction, and heat generated in the real-world, high-speed processes that manufacturers regularly use. NIST is working to measure the basics of these processes at the tool/material interface and figure out how to control them for some desired output. Such details can be incorporated into computer models long before the first prototype is built. Similarly, NIST is working to identify basic measurement and standards needs to model and improve new, revolutionary material additive processes, such as laser sintering of metals, to fabricate highly complex parts.

The second barrier is a lack of fundamental measurement techniques and standards for the intricate motions of manufacturing equipment. Manufacturing equipment that builds complex components on the factory floor -- such as the turbine blades for an engine -- may execute a series of actions on up to five separate axes, and each action must be accurate and fully coordinated with the others. Project researchers are working to establish standards for measuring the accuracy of these complex motions.
 
The third barrier is the difficulty of quickly assessing the geometrical accuracy and acceptability of each finished product. After they are built, products are typically moved to specialized inspection equipment for testing, a step that can be particularly costly for large pieces such as an airplane wing. This project is developing ways to verify fabricated components in place (on the equipment where they are fabricated), saving not only money, but time -- a crucial factor in the race to get new innovations speedily off the shop floor and into the hands of consumers.

Consumer desires change rapidly in today’s marketplace, but it can take up to two years for something like a new car concept to reach the showroom floor. NIST’s efforts in overcoming the three barriers to rapid manufacturing of highly complex, high value products will keep U.S. manufacturing industry the largest in the world.

• Completed comprehensive literature study on metal-based additive processes and interacted with system users to identify the current state-of-the-art and challenges. Evaluated typical part errors and use of test parts as the basis for new standards to characterize the performance of additive manufacturing systems.
• Contributed to two milestone events for advancing additive manufacturing capabilities: initiation of first-ever standards activities for additive manufacturing through the newly-formed ASTM F42 (Additive Manufacturing Technologies) committee and development of a roadmap with industry experts to set priorities and guide additive manufacturing research over the next 10-12 years.
• Demonstrated the successful operation of a newly developed in-situ measurement system for cutting tool dynamics ensuring efficient stable machining processes, greatly reducing time and expertise necessary to conduct such measurements by machine operators on the shop floor.
• Reduced the measurement uncertainty of infrared micro-videography for measuring the temperature distribution of the cutting zone during orthogonal cutting, enabling temperature measurement of small features such as the shear zone. Results are used to improve predictive models of machining processes.
  Completed characterization of material properties of titanium alloy at cutting conditions. The experimental data is used to develop a science-based understanding of differences in machineability.
• Conducted, in collaboration with Kennametal, high-speed micro-videography experiments for the effects of tool insert geometry on material flow and other phenomena in the cutting zone to aid development of new cutting tools.
• Contributed towards the first-ever ISO draft standards in two critical areas that respond to industry needs for high-precision complex products:
• • Standard test methods for evaluating the accuracy of 5-axis complex motion for a new generation of 4- and 5-axis machine tools (ISO/CD 10791-6, Test Conditions for Machine Centers),
  • Standard test methods for evaluating on-machine measuring performance of machine tools using touch-trigger probes (ISO/DIS 230-10, Test Code for Machine Tools).