Effect of bonding temperature and holding time on properties of hollow structure diffusion bonded joints of TC4 alloy

Abstract

The hollow structure commonly used in aerospace field is generally formed by the SPF/DB, but its disadvantages lead to surface groove and complex internal structure difficult to form. In this paper, the method of milling combined with diffusion bonding is used to improve the defect. Diffusion bonding of TC4 titanium alloy hollow structure was carried out at temperature ranging from 800 °C to 900 °C for 10 ~ 30 min. The interfacial bonding ratio, deformation ratio, microstructures, microhardness and mechanical properties of the diffusion bonded joints were investigated. The results show that joints with high bonding quality can be obtained when bonded at 850 °C and 900 °C for 20 ~ 30 min. The joint bonding ratio is more than 92%, the tensile strength is 952 MPa, and the deformation ratio is maintained at about 10%. The microhardness of the TC4 alloy hollow structural joint increases with the increase in bonding temperature, showing a trend of "high in the middle and low on both sides", and it has a peak value (HV472) when bonding time is prolonged up to 30 min. The findings indicate that qualified workpiece can be obtained by the process.

Evaluation of Tungsten—Steel Solid-State Bonding: Options and the Role of CALPHAD to Screen Diffusion Bonding Interlayers

“…The holding time is another very important parameter for determining the strength of diffusion bonding as it can be understood from Equation (2). In previous studies [30,[79][80][81][82], an increase in holding time increased the strength of the bond. Time is required to fill up the pores in the mating surface in order to establish a sound bond.…”

One-Step Hybrid Bending/Diffusion Bonding Process and Analysis of the Bonding Characteristics of Titanium Alloy Sheets

“…To quantitatively determine the degree of bonding, the bonding ratio, thickness strain, and shear strength under each condition are determined and listed in Table 6 and To quantitatively determine the degree of bonding, the bonding ratio, thickness strain, and shear strength under each condition are determined and listed in Table 6 and shown in Figure 17. Thickness strain is the ratio of the reduced thickness after the HB/DBP, and the bonding ratio is the ratio of the total length of the joint interface, except for the total length of the void, which was calculated using an OM (BX53MRF-S) with an image analysis program (ZOOTOS LeopardPro) [43]. Under condition B, almost no deformation occurred throughout the thickness (0.12%), and the bonding ratio (34.44%) and shear strength (895 MPa) were relatively low.…”

“…shown in Figure 17. Thickness strain is the ratio of the reduced thicknes and the bonding ratio is the ratio of the total length of the joint inter total length of the void, which was calculated using an OM (BX53MR analysis program (ZOOTOS LeopardPro) [43]. Under condition B, alm occurred throughout the thickness (0.12%), and the bonding ratio strength (895 MPa) were relatively low.…”

The Effect of Grain Size on the Diffusion Bonding Properties of SP700 Alloy

“…Superplasticity refers to the ability of certain alloys to undergo extensive tensile strain at a specific temperature and strain rate [5][6][7]. Diffusion bonding involves complex boundary migration and plastic deformation [8][9][10][11]. While most works currently focused on the superplasticity of steels and ferrous alloys [12][13][14][15], very limited research has investigated the diffusion bonding process [16][17][18].…”