Research on the diffusion bonding of ( )similar joints of zirconium (Zr) alloys is limited as compared to that on the diffusion bonding of ( )dissimilar joints. The similar Zr alloys are difficult to bond together owing to its high melting point; however, an added interlayer can solve this problem. This study demonstrated the successful vacuum diffusion bonding of the Zr-2.5Nb (Zr705) alloy with a Cu interlayer at 900–960 °C and analyzes the microstructure and mechanical properties of the diffusion-bonded joints. The layered morphology of the joints at 900 °C and 920 °C is attributable to the formation of intermetallic compound layers ( ). In contrast, no such formation was observed at 940 °C and 960 °C owing to the complete diffusion of Cu atoms into the Zr substrate. The base material at the bonding temperatures of 900 °C and 920 °C exhibited two different microstructures i.e., a Widmanstätten microstructure near the bonding interface and a duplex microstructure away from the bonding interface. However, the temperatures at 940 °C and 960 °C exhibited an entirely Widmanstätten microstructure. The tensile strength of the joints increased with the bonding temperature, from 78 MPa at 900 °C to a maximum of 603 MPa at 960 °C (joint efficiency = 104.8%), and the elongation first increased and then decreased with the increasing temperature; at 940 °C, it reached 54% that of the original Zr705 alloy.

锆（Zr）合金（）相似接头的扩散结合的研究相对于（）异种接头（扩散）的研究有限。相似的Zr合金由于熔点高而难以结合在一起。但是，添加一个中间层可以解决此问题。这项研究证明了在900–960°C时具有Zr-2.5Nb（Zr705）合金和Cu中间层的成功真空扩散结合，并分析了扩散结合接头的微观结构和力学性能。接头在900°C和920°C下的分层形态可归因于金属间化合物层（）的形成。相反，由于Cu原子完全扩散到Zr衬底中，在940℃和960℃没有观察到这种形成。基材在900°C和920°C的粘合温度下表现出两种不同的微观结构，即靠近粘合界面的Widmanstätten微观结构和远离粘合界面的双相微观结构。但是，在940°C和960°C的温度下完全呈现出Widmanstätten微观结构。接头的抗拉强度随粘结温度的升高而增加，从900°C时的78 MPa升高到960°C时的最高603 MPa（接头效率= 104.8％），伸长率随温度的升高先升高后降低。在940°C时，达到原始Zr705合金的54％。940°C和960°C的温度表现出完全的Widmanstätten微观结构。接头的抗拉强度随粘结温度的升高而增加，从900°C时的78 MPa升高到960°C时的最高603 MPa（接头效率= 104.8％），伸长率随温度的升高先升高后降低。在940°C时，达到原始Zr705合金的54％。940°C和960°C的温度表现出完全的Widmanstätten微观结构。接头的抗拉强度随粘结温度的升高而增加，从900°C时的78 MPa升高到960°C时的最高603 MPa（接头效率= 104.8％），伸长率随温度的升高先升高后降低。在940°C时，达到原始Zr705合金的54％。