液-固混合制备Al-18Si合金的组织及性能  

Microstructure and Properties of Al-18Si Alloys by Liquid-Solid Mixing

作　　者：张心龙[1] 李元东[1,2] 罗影[1] 周宏伟[1] 刘兴海[1] 

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室 [2]兰州理工大学有色金属合金及加工教育部重点实验室

出　　处：《特种铸造及有色合金》2014年第3期260-263,共4页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(51064017)

摘　　要：采用受控扩散凝固技术(CDS)制备Al-18Si合金,研究了液-固混合方式下Al-25Si合金的温度对制备Al-18Si合金组织和性能的影响,探讨了合金的最终凝固组织与耐磨性能和热膨胀性能之间的关系。结果表明,在受控扩散凝固过程中,630℃固态纯Al与850℃液态Al-25Si合金混合所制备的Al-18Si合金中,初生Si相分布均匀,形貌规整,晶粒尺寸最小,耐磨性能最好。630℃固态纯Al和900℃液态Al-25Si合金混合制备的Al-18Si合金的线膨胀系数最小(15.51×10-6℃-1)。Al-18Si合金的耐磨性能主要取决于初生Si相的平均尺寸、形貌和分布。Effects of liquid-solid mixing and mixing temperature of A1-25Si alloy on the microstructure and properties as well as the relationship between microstructure with thermal expansion coefficient and wear resistance of AI-18Si alloy which was prepared by CDS （controlled diffusion solidification） were investigated. The results show that during the CDS, the desirable microstructure with uniformly distributed round primary Si phase can be observed with mixed solid pure-A1 at 630 ℃ with liquid A1-25Si at 850 ℃ alloy, and wear resistance of the alloy exhibits desirable. The lower linear expansion coefficient（ 15. 51 × 10-6℃^-1 from 30 ℃ to 300 ℃ ） of the AI-18Si alloy can be achieved by the mixing of pure-A1 at 630 ℃ and liquid A1-25Si at 900 ℃. The wear resistance of Al-18 alloy Si is mainly dependent on the size , morphology and distribution of primary silicon.

关 键 词：过共晶AL-SI合金 受控扩散凝固(CDS) 线膨胀系数 耐磨性能 

分 类 号：TG292[金属学及工艺—铸造]