Microstructure and mechanical performance of W base candidate shielding materials sintered by HIP

With the development of fusion devices towards compact designs, the space available for shielding is more limited. So high performance shielding materials are urgently needed to meet the shielding requirements. W-B-Fe-Cr-C Reactive Sintered Borides (RSB) has attracted attention as a potential advanced shielding material for fusion reactors. In this study, the hot isostatic pressing (HIP) sintering process was used to obtain uniform, dense and crack-free RSB at a temperature as low as 1250 ℃. Combined with the microstructure and phase distribution characterization, the influence of microstructure on the performance parameters was analyzed. Although the brittle phase content is higher than similar shielding material, the fracture toughness of RSB-HIP does not decrease due to crack branching, crack bridge and micro-crack toughening mechanisms. The bending strength is only 330 MPa due to the initiation of more cracks in brittle phases during the bending process. The reference and direction are provided for the optimization of preparation process of advanced shielding materials for fusion reactor.