AlTiB纳米细化剂对ZL101合金力学及阻尼性能的影响

Effect of AlTiB Nano-Grain Refiner on Mechanical Property and Damping Capacity of ZL101 Alloy

利用原位自生法合成的纳米晶粒细化剂,成功的克服了颗粒团聚,有效的抑制了颗粒的沉降。本试验用其对ZL101合金的细化行为进行了研究。试验结果表明:加入量为0.2%(质量分数)时,纳米晶粒细化剂可有效地细化初晶α-Al,改善共晶硅的形貌及尺寸,细化后铸态α-Al枝晶尺寸由44μm减小至23μm;经T6处理的细化后试样其拉伸断口为韧窝断口,且韧窝明显多于未细化试样;加入细化剂后保温30min,与未细化合金相比,抗拉强度提高了28MPa,屈服强度提高了22MPa,延伸率增加了2.6%;同时细化后合金的阻尼性能较未细化合金有了大幅提高,0.5Hz时细化后室温阻尼性能Q-1=13×10-3,较之细化前Q-1提高了5×10-3。

Nano-grain refiner produced in-situ synthesis, which overcomes agglomeration and sedimentation of particles successfully, was employed to investigate grain refinement of ZL101 alloy. Experimental findings indicate that α-Al dendritic reduced from 44μm to 23μm in size. Gliding fracture only was observed by SEM on fracture region with grain refinement, which filled with dimple fully. Tensile testing results show that ZL 101 alloy of 30 minutes holding time after additions of nano-grain refiner has the better mechanical properties. Comparing with ZL101 alloy of non-grain refinement, its mechanical properties increase by 28 MPa, 22 MPa, 2.6% in tensile strength, yield strength and elongation respectively. Damping capacity of ZL101 alloy with grain refinement is increased significantly compared with that of the one without refinement. Under condition of room temperature and testing frequency of 0.5 Hz damping capacity after grain refinement is 13×10^-3, increase by 5×10^-3 compared with A356 without refinement at same condition.