In this study, two different compositions of submicron-structured chromium and nickel powders are mixed to fabricate Cr50Ni50 alloys by vacuum hot-press sintering. The research imposes various hot-press sintering pressures (12, 24, 36 and 48 MPa), while the temperature is maintained at 1275 C for 1 h, respectively. The experimental results show the optimum parameters of the hot-press sintered Cr50Ni50 alloys to be 1275 C at 48 MPa for 1 h. The relative density reaches 96.29%, and the hardness and electrical conductivity increase to 75.2 HRA and 2.01 × 10 4 Scm −1 , respectively. Simultaneously, the transverse rupture strength (TRS) value increases to 1109 MPa. Moreover, the Cr50Ni50 alloys dramatically acquire a more homogeneous microstructure, and the mean grain size decreases to 3.48 μm. Consequently, it is shown that hotpress sintering has a positive in uence on the sintering behavior and improves the performance of the refractory metals.

Nanostructured Al-5083/SiC p composites, which consist of an ultrafine grained Al-5083 matrix reinforced with nanosized SiC particles, were fabricated via a cryomilling plus consolidation process. The thermal stability of these composites was studied by investigating the effects of annealing temperature on tensile properties and Vickers hardness of the composites and grain growth in the Al-5083 matrixes, with the annealing temperature ranging up to 873 K. The experimental results indicate that, after annealing at temperatures up to 773 K (0?90T m , where T m is 862 K, the melting onset temperature of the Al-5083 matrixes), the strength of the composites did not decrease significantly, while the grain size of the Al-5083 matrixes did not show a noticeable increase. The grains in some areas of the Al-5083 matrixes did not grow even after annealing at 873 K (1?01T m ). The high thermal stability is attributed to the dispersion of native oxide particles observed at the lamellar interfaces created by cryomilling.

Projection X-ray microscopy (PXM) and transmission X-ray microscopy (TXM) have been established at beamline 31 at the Taiwan Photon Source (TPS). The TPS 31A beamline is sourced by a wiggler with multiple beam modes: white beam, high-flux mono-beam, and high-resolution mono-beam modes. The PXM is based on a collimated beam, and the TXM is full-field microscopy based on a zoneplate. The PXM system and TXM share the same detector platform, which is equipped with different kinds of detector systems for PXM and TXM. The PXM was designed for high-speed 3D tomography with an automatic tray system for loading and unloading samples, including a robotic arm and pre-alignment system. Both the PXM and TXM systems were designed for use in situ, which requires longer working distance for the sample’s environmental cell.

Study on the MicroStructure, electrical and Mechanical ProPertieS of hot PreSSing cr-50 MaSS% ni alloyS fabricated by addition of VariouS ratioS of nanoSized ni PowderSin this work, nanosized ni (nni) powders of 50 nm are mixed with Cr and ni submicron-powders (600 nm) to fabricate Cr-50 mass% ni alloys by vacuum hot pressing. in order to evaluate the influence of the nanosized ni powders, different amounts of nanosized ni powders are added to produce the Cr-(50-x) mass% ni-x mass% nni alloys (x = 0, 10, 20 , and 30). The hot pressing was maintained at 1275°C, 48 MPa for 1 h. The microstructure evaluation, mechanical, and electrical properties were performed. The results reveal that mechanical and electrical properties are enhanced when increasing the nni addition. The Cr-20 mass% ni-30 mass% nni presents the highest relative density of 96.53% and the electrical conductivity of 2.18×10 4 Scm -1 , moreover, the hardness and transverse rupture strength values increase to 76.1 hRa and 1217 MPa, respectively. Moreover, a more homogeneous microstructure and a decrease in the mean grain size to 3.15 μm are acquired. Significantly, this fabrication procedure (adding 30 mass% nanosized nickel powders) results in the optimal microstructure, electrical and mechanical properties of submicronstructured Cr-(50-x) mass% ni-x mass% nni alloys.