纳米TiN/Ti细化剂对Al-4Cu合金组织与性能的影响  

Influence of Nano TiN/Ti Composite Grain Refiner on the Microstructures and Properties of Al-4Cu Alloy

作　　者：李玉洁[1] 李欣蔚[1] 干路 蔡思祺[1] 罗强[1] 蔡启舟[1] 

机构地区：[1]华中科技大学材料成形及模具技术国家重点实验室

出　　处：《特种铸造及有色合金》2013年第6期570-574,共5页Special Casting & Nonferrous Alloys

摘　　要：采用高能球磨法制备了纳米TiN/Ti复合晶粒细化剂,研究了该细化剂对Al-4Cu合金的铸态组织及固溶时效后性能的影响,并探讨了复合细化剂的细化机理。结果表明,纳米TiN/Ti复合细化剂对Al-4Cu合金的铸态组织有明显的细化效果,添加0.2%的TiN/Ti细化剂的合金中α-Al相平均尺寸由161μm细化至131μm,且细化效果优于纯Ti。经过固溶时效处理后,添加TiN/Ti细化剂试样的时效硬度(HV)峰值为125,比未添加细化剂时提高了19%,其抗拉强度和屈服强度比未添加细化剂的Al-4Cu合金试样分别提高了103.1%和155.42%,且添加了TiN/Ti细化剂的试样拉伸断口形貌由未添加细化剂的韧窝-准解理混合型断口转变为韧窝型韧性断口。A new-type nano-sized TiN/Ti composite grain refiner was prepared by high energy ball mill- ing. Influences of the refiner on the as-cast microstructures and properties of Al-4Cu after solid solution and aging were investigated, and the grain refining mechanism was also discussed. The results show that TiN/Ti composite refiner exhibits the excellent grain refining effects on as-cast microstructure of A1-4Cu alloy. TiN/Ti composite refiner can refine significantly the a-phase, and with 0.2% addition, average grain size of a-phase in Al-4Cu sample is decreases from 161 μm to 131 μm, showing better grain refining effect than pure Ti refiner. The micro-hardness of the aged sample with 0.2% TiN/Ti refiner reaches hardness peak of 125 HV, increased by 19% than that of the sample without any refiners. Comparing with those of the sample without adding grain refiners, the tensile strength and yield strength of the sample with 0.2% TiN/Ti refiner are increased by 103.1% and by 155.42%, respectively. In addition, the fracture of the sample without any refiners is characterized by mixed-rupture of quasi-cleavage and dimples, while the fractured faces of the sample with 0.2% TiN/Ti refiner are characterized by ductile fracture with dimples.

关 键 词：Al-4Cu合金 纳米TiN 晶粒细化 时效强化 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]