喷射沉积沉积态Al-12Zn-2.4Mg-1.1Cu-0.5Ni合金显微组织及性能研究

Microstructure and mechanical property research of as-spray-deposited Al-12Zn-2.4Mg-1.1Cu-0.5Ni alloy

为研究喷射沉积沉积态合金的显微组织及第二相种类,利用喷射沉积技术制备了Al-12Zn-2.4Mg-1.1Cu-0.5Ni铝合金。使用X射线衍射仪、扫描电子显微镜、高分辨透射电子显微镜和X射线能谱仪对沉积态合金进行了研究。研究结果表明:沉积态合金的晶粒尺寸只有15μm左右,第二相主要有Mg(Zn,Cu)2相、L12-Al3Zr相和Al-Fe-Ni相,且Mg(Zn,Cu)2相易在Al-Fe-Ni相周围形核长大。沉积态试验合金抗拉强度最大值为360.3 MPa,延伸率为2.1%,断口分析表明合金的断裂方式主要为沿晶脆性断裂。该研究结果确定了沉积态合金中第二相的分布规律和L12-Al3Zr相与基体的取向关系,为后续变形加工及热处理提供了依据。

In order to investigate the microstructure and second phase type in the as-deposited experiment alloy,an Al-12Zn-2.4Mg-1.1Cu-0.5Ni alloy was prepared by spray deposition.Alloy samples were subsequently researched by the X-ray diffractometer,scanning electron microscope,high resolution transmission electron microscopy（HRTEM） and X-ray energy spectrometer.Experimental results esults show that： the grain size of the as-deposited experiment alloy was only about 15 μm,the second phase of the alloy was composed of Mg（Zn,Cu）2 phase,L12-Al3Zr phase and Al-Fe-Ni phase,and the Mg（Zn,Cu）2 phase was easy nucleated around the Al-Fe-Ni phase.The tensile strength is 360.3 MPa and the elongation is 2.1%,feature of fracture is intergranular brittle fracture.These results reveal the distribution of second phase and crystallographic orientation between the L12-Al3Zr phase and the matrix,providing the basis for the subsequent deformation processing and heat treatment.