Coordinated deformation behavior and gas bulging formability of hot-pressed Ni/Al micro-laminated composite sheet
(1. College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China;
2. Engineering Research Center of Advanced Metal Composites Forming Technology and Equipment of Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China)
2. Engineering Research Center of Advanced Metal Composites Forming Technology and Equipment of Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China)
Abstract: To fabricate NiAl complex thin-walled components, a novel Ni/Al micro-laminated composite sheet (NAMCS) was prepared by vacuum hot-pressing. Based on the uniaxial tensile tests at different temperatures, the mechanical properties of NAMCS were investigated. To clarify the uniaxial tensile coordinated deformation mechanism of NAMCS, the deformed microstructure at different tensile strains was characterized by scanning electron microscopy. The results showed that some cracks formed in NiAl3 and Ni2Al3 layers at a tensile strain of 5%, room temperature and 300 °C. At 600 °C and a tensile strain of 20%, some microvoids were observed in the NiAl3 layers, but no cracks formed in the Ni2Al3 layers until the sample fractured at a tensile strain of 78.7%. This indicated a good coordinated deformation ability. The high-temperature free gas bulging test of NAMCS showed that the limit bulging ratio (the ratio of limit bulging height to die diameter) of NAMCS at 600 °C reached 33.3%, implying good formability.
Key words: Ni/Al micro-laminated composite sheet; mechanical properties; coordinated deformation mechanism; gas bulging; formability