結果顯示，A201合金添加TiB_2時，TiB_2顆粒會成為鋁基地異質成核點使晶粒產生細化。三種合金經T7時效處理後造成Ω及θ^′強化相析出，使得合金硬度及強度提升。而合金B和合金C因TiB_2於基地中有散佈強化效果，合金硬度及強度隨TiB_2含量的提升而增高，且延性也同時提升。 ;A201(Al-Cu-Mg-Ag) alloy is classified as a heat treatable high strength aluminum alloys ,the precipitation strengthening effect is achieved by the precipitation of Ω phase and θ^′phase. It has been found that addition of Al-Ti and Al-B master alloys in aluminum alloys can form in-situ TiB_2 particles during casting.TiB_2 particles act as the heterogeneous sites during solidification lead to the reduction in grain size ,thus improved the mechanical properties of the alloy.
Effect of TiB_2 additions on microstructure, mechanical and casting properties of A201 alloys were investigated. Experimental design into three alloys, respectively, alloy A(A201), alloy B(A201+1wt%TiB_2), alloy C (A201+2wt%TiB_2). After T7 treatment, using Optical Microscopy(OM), Scanning Electron Microscopy (SEM), X-ray diffraction(XRD), Electrical Conductivity Meter(%IACS), Rockwell Hardness Test and Tensile Test analyze the effect of TiB_2 addition on microstructures and properties of alloys.
Experimental results indicate that addition of TiB_2 in A201 alloys produces grain refinement due to TiB_2 particles can act as the heterogeneous sites during solidification. After T7 treatment, the hardness and strength of these three alloys increase by the precipitation of Ω and θ^′phase. For alloy B and alloy C, due to TiB_2 particles disperse in the Al matrix enhance the hardness and strength with increase in the amount of TiB_2; furthermore, ductility also improved.
