Roentgenoscopy of laser-induced projectile impact testing.

Laser-induced projectile impact testing (LIPIT) based on synchrotron imaging is proposed and validated. This emerging high-velocity, high-strain microscale dynamic loading technique offers a unique perspective on the strain and energy dissipation behavior of materials subjected to high-speed microscale single-particle impacts. When combined with synchrotron radiation imaging techniques, LIPIT allows for in situ observation of particle infiltration. Two validation experiments were carried out, demonstrating the potential of LIPIT in the roentgenoscopy of the dynamic properties of various materials. With a spatial resolution of 10 µm and a temporal resolution of 33.4 µs, the system was successfully realized at the Beijing Synchrotron Radiation Facility 3W1 beamline. This innovative approach opens up new avenues for studying the dynamic properties of materials in situ.

In situ observation of crystal rotation in Ni-based superalloy during additive manufacturing process.

Understanding the dynamic process of epitaxial microstructure forming in laser additive manufacturing is very important for achieving products with a single crystalline texture. Here, we perform in situ, real-time synchrotron Laue diffraction experiments to capture the microstructural evolution of nickel-based single-crystal superalloys during the rapid laser remelting process. In situ synchrotron radiation Laue diffraction characterises the crystal rotation behaviour and stray grain formation process. With a complementary thermomechanical coupled finite element simulation and molecular dynamics simulation, we identify that the crystal rotation is governed by the localised heating/cooling heterogeneity-induced deformation gradient and recognise that the sub-grain rotation caused by rapid dislocation movement could be the origin of granular stray grains at the bottom of the melt pool.

In situ transient Laue x-ray diffraction during high strain-rate tension.

In situ transient synchrotron Laue x-ray diffraction based on high-energy and broadband x rays under high strain-rate tensile loading was developed at a superconducting wiggler beamline at the Beijing Synchrotron Radiation Facility. A split-Hopkinson tensile bar is utilized to realize this dynamic loading condition, while the transient Laue x-ray diffraction captures the transient internal structure of monocrystalline materials. Plastic deformation of a monocrystalline nickel specimen was investigated to prove the ability of this instrumentation in the characterization of a dynamic response of monocrystalline materials during a high strain-rate impact process with 5 µs time resolution.