本研究藉由光學顯微鏡(OM)、導電度量測(%IACS)、穿透式電子顯微鏡(TEM)與掃描式電子顯微鏡(FEG-SEM+EBSD) 對合金微結構之分析，並以洛氏硬度與拉伸試驗對合金機械性質進行測試，探討微量錳與均質化熱處理對Al-7Mg-0.15Ti合金(B535.0)微結構與機械性質之影響，期能細化合金晶粒，並在退火態抑制合金晶粒成長之現象，同時提升合金之機械強度。 結果顯示，Al-7Mg-0.15Ti合金中添加錳元素能使合金鑄態與再結晶之晶粒細化，並在均質化過程中會在鋁基地中析出細小的Al4Mn之高溫穩定散佈相顆粒。在退火時散佈的Al4Mn顆粒可在再結晶晶粒成長時阻擋晶界的移動，並在晶粒成長時呈現無成長之情況，導致退火態合金具有細晶及散佈強化之效果；添加錳之合金經過兩段式均質化，Al4Mn顆粒相較一段式均質化細小且緻密，其退火時合金抑制晶粒成長之效果明顯高於一段式均質化合金；而未含錳合金，在退火時，再結晶之晶粒呈現正常成長，不同均質化製程對合金之微結構與機械性質均無顯著差異。 ;Microstructure and mechanical properties of Al-7Mg-0.15Ti (B535.0) alloy after Mn addition and homogenization treatment are investigated in detail by optical microscope (OM), transmission electron microscope (TEM), electron backscatter diffraction (SEM-EBSD), electrical conductivity meter (%IACS), Rockwell hardness test and tensile test. The purpose of present work is to refine the grain size, to enhance the strength and to inhibit recrystallization and grain growth after annealing. It is showed that Mn impurity lead to grain refinement. Fine and stable Al4Mn is found precipitating in aluminum base in Al-7Mg-0.15Ti alloys after homogenization. The precipitates inhibit the grain growth by blocking the movement of grain boundary. It causes no grain growth and enhances the strength by grain refinement strengthening and dispersion strengthening after annealing. For alloy with minor Mn, two-stage homogenization gets smaller and denser Al4Mn dispersoids than one-stage homogenization. Fine Al4Mn dispersoid particles have positive effect on inhibiting grain growth. Without Mn addition, two-stage homogenization takes less increasing in mechanical properties. The grains tend toward normal grain growth.
