摘要
探讨钕的添加对AZ71镁合金的力学性能和塑性加工性能的影响。添加0.5%~2.0%的钕时,AZ71镁合金的晶粒尺寸和脆性β-Mg17Al12相的含量均随着钕添加量的增加而降低,并形成纳米级的AlxNdy析出相。经过32%旋锻和退火后,加钕AZ71镁合金的晶粒尺寸由350μm减小到30μm以下。当钕的添加量达到1%时,合金的强度与延性可同时获得提升;当钕的添加量超过1%时,组织中杆状Al11Nd3以及块状Al2Nd聚集析出,导致合金的强度与延性降低。因此,1.0%钕添加量为AZ71镁合金的最佳添加量,添加1.0%钕的AZ71镁合金可以获得253MPa的抗拉强度和10.7%的伸长率,在铸态或经旋锻退火后均具有最高的韧性。
The effects of Nd addition on the mechanical properties and plastic deformability of AZ71 Mg alloys were investigated.0.5%-2.0%（mass fraction） Nd was added to AZ71 Mg alloys.The grain size and the amount of brittle β-Mg17Al12 phase reduce with increasing the Nd addition,while nanosized AlxNdy precipitates form.In combination with 32% rotary forging and subsequent annealing,the grain size of Nd-added AZ71 Mg alloys reduces greatly from over 350 μm to below 30 μm.Both tensile strength and ductility increase with the Nd addition up to 1.0%.The addition of Nd beyond 1.0% leads to the aggregations of rod-shaped Al11Nd3 and blocky Al2 Nd precipitates,thereby deteriorating both strength and ductility.The 1.0% Nd-added AZ71 Mg alloy shows tensile strength up to 253 MPa and elongation of 10.7%.It is concluded that adding 1.0% Nd to AZ71 Mg alloy yields the optimum toughness,whether under as-cast or rotary forging and annealing conditions.
基金
supported by the Ministry of Science and Technology of Taiwan under research grant No.MOST 103-2221-E-027-009
Foxconn Technology Group
关键词
AZ71镁合金
钕
旋锻
力学性能
再结晶
AZ71Mg alloys
Nd
rotary forging
mechanical properties
recrystallization
