An instrument for in situ time-resolved X-ray imaging and diffraction of laser powder bed fusion additive manufacturing processes

作者：Calta Nicholas P; Wang Jenny; Kiss Andrew M; Martin Aiden A; Depond Philip J; Guss Gabriel M; Thampy Vivek; Fong Anthony Y; Weker Johanna Nelson; Stone Kevin H; Tassone Christopher J; Kramer Matthew J; Toney Michael F; Van Buuren Anthony; Matthews Manyalibo J

来源：Review of Scientific Instruments, 2018, 89(5): 055101.

DOI：10.1063/1.5017236

In situ X-ray-based measurements of the laser powder bed fusion (LPBF) additive manufacturing process produce unique data for model validation and improved process understanding. Synchrotron X-ray imaging and diffraction provide high resolution, bulk sensitive information with sufficient sampling rates to probe melt pool dynamics as well as phase and microstructure evolution. Here, we describe a laboratory-scale LPBF test bed designed to accommodate diffraction and imaging experiments at a synchrotron X-ray source during LPBF operation. We also present experimental results usingTi-6Al-4V, a widely used aerospace alloy, as a model system. Both imaging and diffraction experiments were carried out at the Stanford Synchrotron Radiation Lightsource. Melt pool dynamics were imaged at frame rates up to 4 kHz with a similar to 1.1 mu m effective pixel size and revealed the formation of keyhole pores along the melt track due to vapor recoil forces. Diffraction experiments at sampling rates of 1 kHz captured phase evolution and lattice contraction during the rapid cooling present in LPBF within a similar to 50 x 100 mu m area. We also discuss the utility of these measurements for model validation and process improvement.

• 出版日期2018-5