[China Instrument Network Instrument R&D] Recently, the National Institute of Standards and Technology (NIST) engineering laboratory and physical measurement laboratory jointly developed an additive manufacturing measurement test platform. The measurement instrument has many functions, and its system includes collecting the molten pool. A hemispherical shape reflectometer that reflects light information, a spectrometer that can measure all visible spectra and 10 micron wavelength infrared spectra.

3D printing

3D printing of metal parts is a new industry. In 2015, the market value of 3D printing products and services exceeded US$2.3 billion, an increase of nearly five times that of 2010. 3D printed metal parts, that is, over a few minutes or hours, sequentially, layer by layer, and sometimes tens of thousands of layers are stacked together to make a single part, known as additive manufacturing. One of the requirements of additive manufacturing users is to better control the process of 3D printing. This requires some basic difficulties, including the temperature of the molten metal in each layer; how to reduce the pressure that can cause cracking and warping; and what sensors are needed to better understand what is happening inside the printer.

In response to these problems, the National Institute of Standards and Technology (NIST) Engineering Laboratory and the Physical Measurement Laboratory jointly developed an additive manufacturing measurement test platform, a customized 3D printer, to better understand the additive manufacturing process. Their goal is to delve deeper into the manufacturing process and produce tools that users can use to monitor the manufacturing process in real time. The test platform system is similar in size to a small car and operates in a similar manner to a commercial additive manufacturing system. Currently, three different metals can be printed: stainless steel, cobalt chromium, and nickel alloy. The test platform is completely open to researchers.

Since the problems of additive manufacturing processes are often caused by metal melting, NIST needed to find a way to accurately measure the so-called “pool” temperature, which is the pool of metal liquid produced when the laser heats the powder. For this reason, NIST sets the brightness measurement and eventually changes the relative observation of the bath oscillations to an absolute measurement, using the brightness and other properties to measure the actual bath temperature. Currently, NIST uses a custom achromatic lens camera to measure the bath's brightness. In the next year and a half, NIST will further manufacture solution, powder, and solid temperature and reflectometers.

(Original title: U.S. Develops 3D Print Test Platform)