http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Ran Tao,Yutao Zhao,Gang Chen,Xizhou Kai 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.12
Particle-reinforced aluminum matrix composites (PRAMCs) always show a low forming stability because the particles areeasily separated from the matrix, leaving voids and forming cracks. Extruded in situ PRAMCs are gradually replacing ex situPRAMCs due to the higher interface bonding between the in situ reinforcements and matrix. In this study, a hot-extrudedin situ AA6111 composite with ZrB2nanoparticles was obtained from an Al-Zr-B system. The effects of the ZrB2contenton the geometrically necessary dislocation (GND) density, grain size, grain boundaries, textures and tensile properties ofAA6111 composites were researched. The results showed that as the volume fraction of ZrB2increased, the mean GNDdislocation density increased from 1.53 × 1015m−2 to 3.23 × 1015m−2, and most dislocations were located around the ZrB2nanoparticle clusters. In addition, an increase in the ZrB2content decreased the frequency of high-angle grain boundaries(HAGBs) from 79.28 to 69.45% and increased the frequency of low-angle grain boundaries (LAGBs). ZrB2nanoparticleclusters which were located along the grain boundaries promoted continuous dynamic recrystallization (CDRX) and remarkablyrefined the grains, with the mean size decreasing from 48.2 to 1.8 μm. However, dispersed ZrB2nanoparticles inside thegrains suppressed CDRX. Tensile tests showed that the properties rose dramatically with an increasing volume fraction ofZrB2,and the optimum ultimate tensile strength (UTS), yield strength (YS) and elongation (El) of the 2 vol% ZrB2/AA6111composite were 365 MPa, 280 MPa, and 25.6%, respectively. The mechanisms for CDRX, strengthening and plasticityenhancement were determined and discussed.