Production of steel 1006 wire reinforced aluminum base composite by explosive welding

Maryam Roudbari, Nima Refahati*, Ali Mehdipour Omrani

Renewable Energy Research Center, Damavand Branch, Islamic Azad University, Damavand, Iran

*Corresponding author: nimarefahati@yahoo.com

1. INTRODUCTIONTOP

The explosive welding (EXW) technique was used for the first time in World War I (Patterson, 1993). It was at first recognized by Carl in 1944 and then presented into the industry by Philipchuck in 1957 (Honh-bo et al., 2014). The EXW is a solid state process that uses an explosion of explosive material. The flyer plate hits at a specified distance and collides to the base plate (Bataev et al., 2012; Roudbari et al., 2013). A parallel system in the welding process is shown in Fig. 1. (Gulenc et al., 2016).

The EXW was used to produce multi-layer metals in the form of tubes or plates (Mendes et al., 2013). Moreover, this method was not limited by a variety of metals (Xunzhong et al., 2013). Also in order to manufacture composite reinforced by wire, the EXW were used (Los et al., 2010; Huagui et al., 2017).

The quality of the bonding is dependent on many parameters. The main parameters are the collision velocity, the collision angle, the standoff, etc. (Akbari Mousavi and Al-Hassani, 2008). Due to the fact that the explosive welding is perfected in a very brief time at high temperature and high pressure (Pronichev et al., 2016). So, it is hard to be seen and measured some data directly in a test, and the time history seems hard to realize as well (Los et al., 2010).

Thanks to the advance of software, the finite element method (FEM) has been applied to the study of the EXW (Los et al., 2010). Li et al. (2017) studied the numerical simulation of a Titanium/Aluminum laminated composite was manufactured by explosive welding. In a similar work, Aizawa et al. (2016) investigated joining Al/Fe using numerical analysis and experimental analysis. Nassiri et al. (2015a) predicted the weldability window of parameters by using the finite element simulation. A test was done to verify the simulation and weldability window.

In this study, the optimum operational parameters were predicted to prepare the excellent interface by the weldability window and the numerical analyses. The materials selected for this study were Al1050 and Steel1006. The purpose of this paper is to fabricate Steel wire reinforced Aluminum composite plate with no crack and an acceptable bond.

2. MATERIALS AND METHODSTOP

2.1. Explosive welding modelTOP

Numerical simulation of explosive welding was applied by AUTODYN version 14. In this study, Aluminum plates were chosen for the flyer plate and the base plate and the steel wires as reinforcing. A 3D model for the composite set simulation is shown in Fig. 2.

The model has included four materials, such as Aluminum, Steel, Aluminum, and Anfo. The measuring units are used in the AUTODYN, i.e. The length unit is mm, the time unit is ms and the mass unit is mg, the colors of the materials are different in the Autodyne, i.e., the explosive is blue; the flyer plate and the parent are green; the wire is red.

The Johnson-Cook (JC) equation (Nassiri et al., 2015b) was applied for the Al1050 (flyer plate and the parent plate). This equation explains the behavior of material exposed to large deformation (Nassiri et al., 2015b); it can be estimated as follows:

with

where Y is the yield stress, ԑ is the effective plastic strain, ԑ* is the normalized effective plastic strain rate (often equal to 1), Troom is room temperature, Tmelt shows the melting point of materials and A, B, C, n, and m are the constant equation. The material constants are as listed in Table 1.

The Jones-Wilkins-Lee (JWL) equation of state was applied for the ANFO explosive (Nassiri et al., 2015a). The JWL represents pressure as a subordinate of volumetric strain and special interior energy. The JWL equation is (Los et al., 2010):

where P is the pressure, V represents the relative volume, E is internal energy, w is the Gruneisen parameter, and A, B, R1, R2, are constants of explosive, as shown in Table 2 the default ANFO Constants (Los et al., 2010). The material constants were extracted from the AUTODYN material library.

2.2. Weldability window calculations TOP

There were conditions in the explosive welding that must be met to get proper welds to explain what was named the weldability window/criteria, the weldability zone was developed by Cowan et al. (Cowan et al., 1971; Hoseini-Athar and Tolaminejad, 2015). The quality of the connection depends on the EXW welding parameters (Hoseini-Athar and Tolaminejad, 2015), all of the parameters were plotted in the weldability criteria, It could be plotted in both the collision velocity (V_c) and the collision angle (β) (Ribeiro et al., 2014), (Fig. 3). Deribas (1972) and Yingbin et al. (2017) suggested the lower limit for the weldability window, which subtended.

where in this Eq. (4) β is in radians, k for high-quality is 0.6 and 1.2 for low-quality and 0.85 for normally-a quality which is a constant, H is the hardness of Vickers for the flyer plate expressed in N∙m^-2 and ρ is the density of the flyer plate in kg∙m^-3 (Hoseini-Athar and Tolaminejad, 2015). Cross land and Bahrani proposed a lower limit of the collision angle is 2°-3° and an upper limit of collision angle is 31° (Zakharenko and Zlobin, 1983).

The upper boundary for the weldability window was reported by Deribas (1972), Wittman (1973) and Zamani and Lighat (2012).

In Eq. (5), β is expressed in radian, t is the thickness of the flyer plate expressed in m, V_c is the collision velocity expressed in m·s^-1.

k₃ is related to the mechanical and physical properties of the Al1050 plates. In Eq. (6), ע is Poisson’s ratio, E is the elastic modulus in N·mm^-2 and ρ is the density expressed in kg·m^-3.

The left border of the weldability window was linked to the formation of a wavy interface. This limit can be calculated by Eq. (7) (Song et al., 2011).

Equation (7) in which R_e is equal to 10.6 (Nassiri et al., 2015b), P_f and P_p are the densities of the base plate and flyer plate material in kg·m^-3, H_f and H_p are their Vickers hardness and V_c is the collision velocity.

The right border of the weldability window or the maximum collision velocity estimated at 1.2–1.5 times the sound velocity (Yingbin et al., 2017).

2.3. Experimental procedureTOP

In this paper, the test was carried out using the flyer plate (Al1050), the parent plate (Al1050) set up in a parallel formation. For this particular case, the weldability window was plotted. Welding conditions and material properties were selected according to weldability window presented in Tables 1 and 2. In composite plate manufacture, Steel1006 in the diameter of 1 mm was applied as reinforcement. The Aluminum plate of 250×250×4 mm was utilized as a flyer plate, located 4 mm was upper the base plate. The base plate was provided in the size of 250×250×4 mm. The explosive welding was performed using Anfo, the plates and wire mounted in parallel (Fig. 4). The chemical explosive was placed in a box on the flyer plate and the explosion was located on one end of the carton. Moreover, the Steel wire located at zero degree directions relative to the explosion orientation (Fig. 4).

3. RESULTSTOP

The examples of the simulation of the progress of the explosive are shown in Fig. 5–6. Figure 5 shows the position of the base and flyer plates for test 2 ms after detonation. Figure 6 shows the simulation of the test at 4 ms after detonation.

In this paper, the collision velocity (V_c) and the angle velocity (β) were predicated by AUTODYN.

The weldability window is designed based on the collision angle and the collision velocity. Calculated weldability window for the composite set is shown in Fig. 7. The simulation result is placed in the weldability window properly. (Fig. 7)

The interface bonding modality of Al/Steel/Al was examined by the light microscope. Samples of metallographic observations were sectioned from the explosively welded plates. Figure 8 indicates the light microscope images of the bonding interface. It shows that no crack or fault happens at the interface even in the case of magnification of 200 times.

In Fig. 8, the stainless steel wire is located in the middle of the image, which is a circular shape and the Aluminum is surrounded that it is darker than the wire. It can be observed that the interface of AL/Steel/AL with no void and no macroscope fracture is shown in Fig. 8. The interface showed favorable bonding in the composite plate

4. DISCUSSIONTOP

The collision velocity in the simulation was obtained by dividing the length of the material by the total timing of the simulation process was also in agreement with experiments. Moreover, the relationship between the numerical simulation, the weldability window, and the experiment show that all parameters are suitable. The interface bonding is with no void and no crack which shows a good agreement between the finite element results and the experimental data. Gülenc et al. (2016) produced stainless steel wire reinforced aluminum composite plate by the explosive welding process, respectively, and their bonding showed no crack or no void.

All parameters of the composite set predicted by the simulation and the weldability window were agreed very well with the experiment.

5. CONCLUSIONSTOP

In this paper, the weldability window of Al1050/Al1050 was calculated. On this basis, Aluminum base composite reinforced with steel wires were successfully prepared by the explosive welding process and the image of the light microscope with no void was also confirmed the perfect connection Al/steel/Al. The results of the experiments and numerical simulation were perfectly compatible.

REFERENCESTOP