Evaluation of ultra-fine grained tungsten under transient high heat flux by high-intensity pulsed ion beam
(1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China;
2. School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China;
3. School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China)
2. School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China;
3. School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China)
Abstract: Pure tungsten, oxide dispersion strengthened tungsten and carbide dispersion strengthened tungsten were fabricated by high-energy ball milling and spark plasma sintering process. In order to evaluate the properties of the tungsten alloys under transient high heat flues, four tungsten samples with different grain sizes were tested by high-intensity pulsed ion beam with a heat flux as high as 160 MW/(m2∙s−1/2). Compared with the commercial tungsten, the surface modification of the oxide dispersion strengthened tungsten by high-intensity pulsed ion beam is completely different. The oxide dispersion strengthened tungsten shows inferior thermal shock response due to the low melting point second phase of Ti and Y2O3, which results in the surface melting, boiling bubbles and cracking. While the carbide dispersion strengthened tungsten shows better thermal shock response than the commercial tungsten.
Key words: tungsten; tungsten alloy; ultra-fine grain; surface effects; thermal shock; transient high heat flux