性能的影響
王明星，謝敬佩，翁永剛
( 鄭州大學(xué) 物理工程學(xué)院，材料物理教育部重點實驗室，
鄭州 450052 )
摘 要: 研究了不同鈦含量的電解A356合金的組織和力學(xué)性能，并與相應(yīng)鈦含量的熔配加鈦A356合金進(jìn)行了比較。結(jié)果表明：隨著鈦含量的增加，二者的晶粒和一次枝晶都明顯細(xì)化，硅顆粒尺寸、縱橫比均有所降低，硅顆粒圓形度有所增加，意味著硅顆粒形狀得到改善。但當(dāng)鈦含量大于0.1％時，這種影響變?nèi)酢ｂ伜亢图逾伔绞綄辖鸬那䦶?qiáng)度和抗拉強(qiáng)度影響不大且二者相當(dāng)，但塑性隨著鈦含量的增加而增加，當(dāng)鈦含量達(dá)到0.1％時，兩種合金均具有最佳的塑性和質(zhì)量系數(shù)。對具有相同鈦含量的合金，電解加鈦A356合金的晶粒和Si顆粒的尺寸小于相應(yīng)鈦含量熔配加鈦A356合金，硅顆粒圓形度也優(yōu)于相應(yīng)熔配加鈦A356合金，電解A356合金的塑性、質(zhì)量系數(shù)均優(yōu)于相應(yīng)鈦含量的熔配加鈦A356合金，但加鈦方式對硅顆粒縱橫比影響不系統(tǒng)。
關(guān)鍵字: 加鈦方式；鈦含量；A356合金；微觀組織；力學(xué)性能
microstructure and mechanical properties of A356 alloys
SONG Tian-fu, WANG Ming-xing,
XIE Jin-pei, WENG Yong-gang
（ School of Physics Engineering, The Key Lab of Material Physics, Ministry of Education,
Zhengzhou University, Zhengzhou 450052, China）
Abstract: The microstructure and mechanical properties of electrolytic A356 alloys with different titanium contents were investigated and compared with those of A356 alloys alloyed by melting Al-Ti master alloys. The results show that the grain, primary dendrite and Si particles of both kinds of alloys are obviously refined with increasing titanium content. The aspect ratio decreases and the roundness of Si particles increases, which means that the shape of Si is improved. This effect on the microstructure decreases when titanium content exceeds 0.1%. The effects of titanium content and titanium alloying manner on the yield strength and tensile strength of alloys are trifling, but the ductility increases with increasing titanium content. Two kinds of alloys have the optimal elongation and quality index when titanium content approaches 0.1%. For the alloys with the same titanium content, the sizes of grain and Si particles of electrolytic A356 alloys are less than those of A356 alloys alloyed by melting Al-Ti master alloys. The roundness of Si particles, the elongation and quality index of the former are superior to those of the latter. The effect of titanium alloying manner on the aspect ratio is unsystematic.
Key words: titanium alloying manner; titanium content; A356 alloys; microstructure; mechanical properties
