The effects of trace Er on the microstructural evolution and mechanical properties of newly designed Al–Zn–Mg–Cu–Zr alloys for drilling pipes were investigated. After homogenization, most of the eutectics dissolved into the matrix and some primary phases remained, including Al₈Cu₄Er, Al₁₂(Mn,Cr), and Al₃Ti. Dispersed nano-sized Al₃(Er,Zr) precipitates were formed in the Er-containing alloys after homogenization. Following extrusion, solution and retrogression re-aging (RRA) treatment, the hardness and yield strength of the 0.10 wt% Er-containing alloy are increased by 14% (25.4 HV) and 12.7% (70 MPa) compared to the alloy without Er. This improvement could be ascribed to the precipitation strengthening of fine Al₃(Er,Zr) particles, which complemented the conventional η' phase precipitation strengthening. The intergranular corrosion resistance of the RRA-treated alloy with the addition of 0.10 wt% Er was improved by 65% due to a lower amount of high angle grain boundaries. The fracture and intergranular corrosion mechanisms in alloys with and without Er addition were linked to the respective grain structures.

研究了微量Er对新设计的用于钻杆的Al-Zn-Mg-Cu-Zr合金的组织演变和力学性能的影响。均质化后，大多数共晶溶解在基体中，并保留了一些主要相，包括Al ₈ Cu ₄ Er，Al ₁₂（Mn，Cr）和Al ₃ Ti。分散纳米Al ₃均质化后，在含Er合金中形成（Er，Zr）沉淀。经过挤压，固溶和回归再老化（RRA）处理后，与不含Er的合金相比，含0.10 wt％的Er的合金的硬度和屈服强度提高了14％（25.4 HV）和12.7％（70 MPa）。 。这种改善可以归因于细小的Al ₃（Er，Zr）颗粒的沉淀强化，它补充了常规的η'相沉淀强化。加入0.10 wt％Er的RRA处理的合金的抗晶间腐蚀性能提高了65％，这是由于较少的高角度晶界引起的。添加和不添加Er的合金的断裂和晶间腐蚀机理与各自的晶粒结构有关。