• 作者： 周安琪; 劉國雄
• 作者服務機構： 國立清華大學材料科學工程系
• 中文摘要： 本實驗是利用穿透式電子顯微鏡與硬度試驗觀察 Al-9% Zn-0.9% Mg-0.13% Zr合金的析出硬化過程及加工對其析出過程的影響。由於合金中含有高量的鋅，時效硬化是由共格的GP域與　相析出所引起。　相與基地的方向關係發現有兩種：(1) (10　0)　// (100)α；(0001) //(01 )α；(2) (10　0)　//(110)α；(0001) //(111)α。當 相變得較大，且　相的析出量較多時，試片的硬度降低，產生過時效。二段時效處理較直接時效處理的硬化效果佳，是因為在低溫的預時效處理時，試片中含有過多的淬火空孔聚集物，　相可很細密均勻地析出在這些空孔上，使得硬度升高。淬火後再滾壓的試片在120　C時效可使硬度值大為增加，在160　C時效無硬化效果“
• 英文摘要： TEM and hardness test have been used tostudy of the precipitation process and the in-fluence of cold work on the precipitation pro-cess in a Al-9%Zn-0.9%Mg-0.13%Zr alloy.The aging hardening effect is caused by the pre-cipitation of coherent GP zones and phase.Two orientation relationships between the phase and the matrix was found in this system:(1)(10 0) //(100)α;(0001) //(O1 )α; (2) (10 0)//(1 0)α; (0001) //(111)α· The overaging isresulted from the coarse and the large amountof precipitates as the aging time is increased.Two step aging produce superior properties thandirect aging, this is because that fine phasecan be homogeneously precipitate on the excessquenching vacancies or vacancy clusters. Theaging at 120 C of the cold worked specimenafter quenching can enhance the precipitationrate and increase the hardness. However, thereis no hardening effect during aging at 160 C.
• 中文關鍵字： --
• 英文關鍵字： --