(廣東省材料與加工研究所，廣州 510650)
摘 要: 采用氣霧化工藝制備Al-5Ti-1B合金粉，然后壓制成Al-5Ti-1B合金，研究了粉末壓制Al-5Ti-1B合金的顯微組織與晶粒細化性能，并與鑄造Al-5Ti-1B合金進行了比較。結(jié)果表明：氣霧化快速凝固可以抑制TiB2粒子的團聚和細化TiAl3相，使TiB2粒子和TiAl3相均勻分布在粉末壓制Al-5Ti-1B合金的α(Al)基體上。在純鋁熔體中添加0.2%(質(zhì)量分數(shù))的粉末壓制Al-5Ti-1B合金并保溫2 min，可使純鋁的晶粒組織從粗大的柱狀晶細化為平均直徑為183 μm的等軸晶。保溫時間延長至180 min，純鋁的晶粒平均直徑仍保持在229 μm。與鑄造Al-5Ti-1B合金相比，粉末壓制Al-5Ti-1B合金具有更強的晶粒細化能力和抗細化衰退能力。
關(guān)鍵字: 晶粒細化劑；Al-Ti-B合金；氣體霧化；粉末壓制；快速凝固
（Guangdong Institute of Materials and Processing, Guangzhou 510650, China）
Abstract:The Al-5Ti-1B alloy powder was prepared by gas-atomization process and then compacted into Al-5Ti-1B alloy. The microstructure and grain refining performance of powder compacted Al-5Ti-1B alloy were studied and compared with that of conventional cast Al-5Ti-1B alloy. The results show that the rapid solidification during the gas-atomization can inhibit the aggregation of TiB2 particles and refine the size of TiAl3 phase. The TiB2 particles and TiAl3 phases are uniformly distributed in the powder compacted Al-5Ti-1B alloy. With adding 0.2% (mass fraction) powder compacted Al-5Ti-1B alloy in the pure aluminum melt and holding for 2 min, the pure aluminum can be refined from coarse columnar grains to fine equiaxed grains with an average diameter of 183 μm. When the holding time is prolongated to 180 min, the average grain diameter of pure aluminum is still remained at 229 μm. Compared with the conventional cast Al-5Ti-1B alloy, the powder compacted Al-5Ti-1B alloy has a stronger grain refining ability and resistance to grain refinement fading.
Key words: grain refiner; Al-Ti-B alloy; gas atomization; powder compaction; rapid solidification
