Int J Adv Manuf Technol DOI 10.1007/s00170-015-8211-y
ORIGINAL ARTICLE
Dissimilar friction stir welding of 7075 aluminum alloy to AZ31 magnesium alloy using SiC nanoparticles M. Tabasi 1 · M. Farahani 1
·
M. K. Besharati Givi 1 · M. Farzami 1 · A. Moharami 2
Received: 18 June 2015 / Accepted: 7 December 2015 # Springer-Verlag London 2015
Abstract In this study, a new approach for dissimilar friction stir welding of aluminum alloy and magnesium alloy was developed. In order to make metal matrix composite in the weld stir zone, silicon carbide nanoparticles were embedded into the weldment. The admixture pattern of the stir zone, weld microstructures, intermetallic phases, powder distribution, and mechanical properties of the welds were investigated in this paper. Due to using silicon carbide nanoparticles as reinforcement in friction stir welding, the weld microstructure was affected by pinning mechanism. Meanwhile, it was observed that the formation of brittle and hard intermetallic phases also affected the welded joint microstructure. The effects of friction stir welding process parameter such as tool rotational and traverse speeds were also examined. It was observed that increasing the tool rotational speed and decreasing the tool traverse speed improved the mixing of two alloys at the stir zone. By controlling the process parameters, a fine microstructure with an average grain size of 4.3 μm at the stir zone was obtained.
Keywords Friction stir welding . Dissimilar Welding . Silicon carbide nanoparticles . 7075 aluminum alloy . AZ31 magnesium alloy
* M. Farahani
[email protected] 1
School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran
2
Faculty of Mechanical Engineering, Imam Khomeini International University, Qazvin, Iran
1 Introduction Magnesium alloys are becoming more and more important as lightweight structural materials in aerospace, automotive and shipbuilding industries. The ability to join the Mg alloy components to other engineering materials such as aluminum alloys would allow further design flexibility and expand their applications [1]. By the way, effective joining of Al and Mg alloys would lead to more weight saving [2]. Improving the ability to join dissimilar materials with engineered properties are enabling new approaches to light-weighting automotive structures, improving methods for energy production, creating next generation medical products and consumer devices, and many other manufacturing and industrial uses. Therefore, dissimilar welding using numerous fusion and solid-state welding methods has been studied [3–5]. Solidification cracks, intermetallic compounds, high amount of residual stresses, and difficult control of the required energy are the main factors that limit the application of fusion welding methods in joining of dissimilar alloys [6–8]. Some of the solid-state welding methods such as ultrasonic welding, diffusion welding, and explosive welding are considered as appropriate alternatives to fusion welding methods for dissimilar joining. But, factors such as dimensional limits, need for specific equipment, high cost of implementation, and high energy consumption limit the application of these methods [9]. Due to the high quality of the weld, lower costs, proper repeatability, and lower energy consumption, the friction stir welding (FSW) method is widely used in dissimilar welding [10]. So far, many researches have been done in order to study the FSW of dissimilar alloys, including different aluminum alloys [11], aluminum to steel [12], aluminum to brass [13], and aluminum to magnesium alloys [14]. Simoncini and Forcellese discussed the effects of the process parameters on weld appearance and mechanical and microstructural
Int J Adv Manuf Technol
properties of similar and dissimilar joints of aluminum 5754 and magnesium AZ31. They observed that locating the aluminum alloy in the advancing side and magnesium alloy in the retreating side led to a higher weld quality [15]. The welded joints of Al 5754 and AZ31 presented a significant decrease in tensile strength and ductility. In fact, the welded samples were characterized by their brittle fracture at small strains in the linear elastic range. In another study, Mofid et al. reported the similar results [16]. One of the most important problems in the dissimilar welding is the formation of intermetallic compounds which decreases the mechanical properties of the welded joint. In joining of aluminum alloys to magnesium alloys, formation of Al12Mg17 and Al3Mg2 intermetallic phases in the solidstate welding was reported by Zettler et al. [17]. These intermetallic phases were considered as the main reason for cracking in these joints. According to the Al-Mg phase diagram, Al3Mg2 and Al12Mg17 intermetallic compounds may form at high welding temperature; the former on the Al side and the latter on the Mg side [18]. The literature on joining of the Al to Mg by FSW indicates the formation of the brittle intermetallic compounds at the Al-Mg weld interface, which results in weakening of the joint with negligible ductility [19]. Over the recent years, friction stir processing (FSP) has been widely investigated. FSP, an outgrowth of FSW, has been employed to produce surface composite layers by using macrosized, microsized, and nanosized reinforcements [20]. Barmouz et al. fabricated Cu-based SiC reinforced composite and observed that increasing rotational speed or decreasing traveling speed, reduced the grain size in stir zone. They also reported that the grain size of the fabricated composite layers were considerably finer than that of the specimen fabricated without the addition of SiC particles [21]. Azizieh et al. investigated the effect of the probe profile, rotation speed, and particle size on the microstructures and hardness of the AZ31/Al2O3. They observed that particle distribution was enhanced with increase of rotation speed. They reported that the grain size of nanocomposite was effectively refined as compared with composite with microparticles, FSPed sample without particles, and initial state of matrix [20]. Dolatkhah et al. found that in FSP of Al5052 with SiC particles, the uniform powder distribution was achieved at rotational speed of 1120 rpm and traverse speed of 80 mm/min [22]. Sun et al. used Sic microparticles for friction stir welding of 2 mm thick copper plates and achieved a copper matrix composite in the stir zone [23]. In this research, a new approach was developed to weld the aluminum 7075 alloy to the magnesium AZ31 alloy reinforced by SiC nanoparticles. The main objectives of this research have been the understanding of effective mechanisms and the evaluation of potential of using nanoparticles in dissimilar friction stir welding of AL 7075 to AZ31. In order to
Table 1
Specification of nano-SiC particles
Purity
Size range
Bulk density
Free C
Free Si
99 %
30-40 nm
0.05 g/cm3
0.78 %
0.21 %
enhance the microstructure of the weld, the effects of friction stir welding process parameter such as tool rotational and traverse speed were also examined.
2 Experimental investigation 2.1 Specimen preparation In this study, specimens with 50-mm width and 70-mm length are cut from 5-mm-thick sheets of 7075-T6 aluminum alloy and AZ31 magnesium alloy. The SiC nanoparticles were employed in order to produce surface composite layers and refine the microstructure of the weld joint. The ceramic type of reinforcements is the most commonly used particles in FSP of magnesium alloys. They range from carbides, borides, and oxides. The most widely investigated and used reinforcing ceramics with magnesium alloys is the SiC particles. It is thermodynamically stable in molten Mg alloys and it has relatively good wettability with Mg in comparison to the other ceramic reinforcements [2]. The specifications of the used SiC nanoparticles are shown in Table 1. 2.2 Friction stir welding Aluminum and magnesium alloys were placed at advancing side and retreating side, respectively. In order to incorporate the SiC nanoparticles into the SZ, a groove at the interface between the two specimens was created by machining. In the other works which used the particles for the friction stir welding, an open surface groove was employed to place the powder (Fig. 1). An additional tool without pin was also required to cover the groove surface and fix the powder before welding. Tools swirling during the welding of specimens with an open surface groove might scatter remarkable proportion of particles. In this study, a new design for this groove was developed. An embedded groove was designed in a way that the
Fig. 1 The new employed powder groove
Int J Adv Manuf Technol Fig. 2 FSW tool with threaded triangular pin
particles were totally locked between the specimens, so there was no powder loss during the welding process. Besides, no additional tool was required for fixing the powder before welding. In Fig. 1, the schematic view of the new designed powder groove for friction stir welding is presented. The tool employed in the welding process constructed from hot worked steel W302 which heat treated to reach to the appropriate hardness. Maximum hardness of W302 hot worked steel is about 56–57 HRC. With this amount of hardness, the tool did not have the required toughness for welding and failed early. According to several trial and error tests carried out in this study, it was found that the acceptable hardness for the above mentioned dissimilar welding was about 45 HRC. A tool with shoulder diameter of 17 mm, pin diameter of 5 mm and pin height of 4.8 mm was used. The tool pin profile plays a major role in the weld quality and tool life. Pin geometry also has an important effect on the admixture pattern of the stir zone. In this study, some primary experiments were conducted to select the applicable tool pin profile. Based on the visual inspection of the prepared welded samples and the observed tool wear, it was concluded that the threaded triangular pin had the better performance and wear resistance. The employed tool geometry is presented in Fig. 2.
Fig. 3 Schematic of the experimental investigation procedure
Selecting the appropriate welding rotational and traverse speeds plays a key role in achieving a highquality welded joint. In order to study the effects of tool rotational and traverse speed on the welding process, a wide range of rotational speed of 450, 560, 710, 900, and 1100 rpm and traverse speed of 11.2, 22.4, 35.5, and 45 mm/min were employed in this study. It was observed that the dissimilar welding of Al to Mg alloy was very sensitive to welding parameter. Based on the visual inspection of 20 prepared welded samples, the specimens with rotational speeds of 560 and 710 rpm and the traverse speed of 22.4 and 35.5 mm/ min had the appropriate weld quality. So, in the following, these levels of rotational speeds and traverse speeds were studied. The other welding process parameters were considered to be constant. Optical microscopy and field emission scanning electron microscopy (FESEM) were used in order to analyze the microstructure of the stir zone and to study the particle distribution in the weldment. Furthermore, energy-dispersive Xray spectroscopy (EDAX) was employed for elemental analysis in stir zone of the specimens. The schematic of the experimental investigation procedure used in this study is presented in Fig. 3.
Int J Adv Manuf Technol Fig. 4 The admixture pattern of the weld stir zone: a RS= 560 rpm, TS=22.4 mm/min; b RS=710 rpm, TS=22.4 mm/ min; c RS=560 rpm, TS=35.5 mm/min
(a)
(b)
(c) 3 Results and discussion The weld joints generated by friction stir welding technique have four different zones: base-metal zone, heatFig. 5 The cross section of samples with TS=35.5 mm/min and a RS=560 rpm, b RS=710 rpm
Mg
affected zone (HAZ), thermomechanically affected zone (TMAZ), and stir zone (SZ)[9]. Dynamic recrystallization and annealing effect of welding heat input are considered as two important phenomena [24]. Severe plastic
Al
(a)
Mg
Al
(b)
Int J Adv Manuf Technol Fig. 6 Microstructure of FS welded joints on the Mg side stir zone: a RS=560 rpm, TS= 22.4 mm/min; b RS=710 rpm, TS=22.4 mm/min; c RS= 560 rpm, TS=35.5 mm/min; d RS=710 rpm, TS=35.5 mm/min
(a)
(b)
(c)
(d)
deformation during the friction stir welding leads to formation of fine grain microstructure in the stir zone. This process is called dynamic recrystallization which is one of the main effective mechanisms on the weld microstructure [25]. Dynamic recrystallization leads to nucleation and decreases the grain size. Besides, severe plastic deformation increases the dislocation density, which prevents the grain boundary from slipping. Another important mechanism which has a significant effect on the weld microstructures is the annealing effects of welding heat input, which depends on tool rotational and traverse speed. Increase in welding heat input leads to grain boundary migration and grain growth, which reduces the weld strength. The nanoparticles in friction stir Table 2
welding pinned the movement of the dislocation and grain boundary. Pinning is the another mechanism which affects the weld microstructures in the friction stir welds containing nanoparticles [25]. Moreover, the presence of
Mean grain size of FS welded samples
Rotational speed (rpm)
Traverse speed (mm/min)
Mean grain size (μm)
560 710 560 710
22.4 22.4 35.5 35.5
8.62 4.36 13.1 8.67
Fig. 7 FESEM micrograph of FS welded sample with RS=710 rpm, TS=22.4 mm/min at the stir zone on the Mg side
Int J Adv Manuf Technol Fig. 8 The FESEM image of friction stir welded sample with RS=560 rpm, TS=35, 5 mm/min: a cross section of the specimen with magnification of ×31, b the area indicated by the circle with magnification of ×400, c EDAX elemental analysis of the point indicated by “A”; d line-scan of the cross section
Mg
Al
(a)
(b)
(c)
(d)
nanoparticles increases the nucleation sites and leads to recrystallization [20]. In dissimilar welding of aluminum alloy to magnesium alloy, formation of brittle and hard intermetallic phases during welding is also one of the effective factors which decrease the strength of the weld [14]. Hence, in order to study the microstructural developments of the weld zone, the formation of intermetallic compounds were also should be considered.
3.1 Admixture pattern of the stir zone The admixture patterns of the weld stir zone for different welding process parameters are shown in Fig. 4. An increase in the tools traverse speed (TS) decreased the quality of material mixing, which is clear in comparison between Fig. 4a, c and Fig. 4b, d. As it is shown in Fig. 4a, b, in constant traverse speed, an increase in the
Int J Adv Manuf Technol Table 3 The elemental analysis of the point indicated by “A”
Element
wt. %
Magnesium Aluminum
61.79 34.82
Silicon
0.68
Zinc
2.70
tool rotational speed (RS) promoted the mixing of the materials. In Fig. 5, the larger views of the cross section of specimen with two different rotational speeds are presented. More plastic deformation with higher welding heat input at higher tool rotational speed mixed the parent materials together more appropriately.
3.2 Grain size of the weldment The microstructures of the stir zone for four different welding conditions are presented in Fig. 6a–d. The average grain sizes in the stir zone of these experiments are also listed in Table 2. By increasing the tool rotational speed, the grain size in the stir zone was decreased significantly. It can be explained by more dynamic recrystallization and better particle distribution at higher tool rotational speed. The distribution of particle was investigated in the following. Increasing the tool traverse speed, as shown in Fig. 6, increased the grain size. By increasing the tool traverse speed, the effects of pinning mechanism decreased. On the other side, the annealing effects were also decreased due to less welding heat input. More
Fig. 9 FESEM image and map of SiC distribution in the FS welded sample with a, b RS=710 rpm, TS=22.4 mm/min, c, d RS= 710 rpm, TS=35.5 mm/min
(a)
(b)
(c)
(d)
Int J Adv Manuf Technol Fig. 10 Particle distribution of FS welded sample with RS= 710 rpm, TS=35.5 mm/min: a cross section, b SiC distribution
Al
Mg
(a) dynamic recrystallization also occurred due to higher compression stress at higher tool traverse speed. Grain growth associated with higher traverse speed is indicative of the fact that pinning effect played the leading role in microstructural evolution. Improved pinning of the particles at lower tool traverse speed decreased the grain size significantly. The optimum microstructure with the finest grain size was observed in the welded sample with rotational speed of 710 rpm and traverse speed of 22.4 mm/min. The FESEM micrograph of this sample is also shown in Fig. 7. A fine and uniform grain with average size equal to 4.36 μm was observed.
3.3 Intermetallic phases in the stir zone Numerous factors such as grain size, dislocation density, probable defects, and particle distribution can affect the properties of the weld joint[21]. Moreover, in dissimilar welding of aluminum to magnesium alloys, another important factor which affects the properties of the weld is the formation of intermetallic compounds at the stir zone[14]. The dark area at the interface of two alloys as shown in Fig. 4, presents the intermetallic compounds which generated during the welding. These compounds were observed in all welded samples. Despite the formation of the fine microstructure in dissimilar friction stir welded joints of aluminum and magnesium alloys, generation of brittle and hard intermetallic phases might decrease the weld quality [26]. Table 4
Mean ultimate tensile strength of the welded samples
Rotational speed (rpm)
Traverse speed (mm/min)
UTS (MPa)
560 710 560 710
22.4 22.4 35.5 35.5
106 98 57 86
(b) It was observed that increasing the tool rotational speed and decreasing the tool traverse speed, increased the welding heat input, which prepared a suitable condition for generating of intermetallic phases. In Fig. 8, FESEM image of the cross section of the welded sample with rotational speed of 560 rpm and traverse speed of 35.5 mm/min is shown. The elemental analysis of point A in Fig. 8b was presented in Fig. 8c and listed in Table 3 which confirms the presence of intermetallic compounds such as Al12Mg17 in the stir zone of the weld. The line analysis of the cross section of this welded sample obtained from FESEM equipped with EDAX is shown in Fig. 8d. Drastic changes in the chemical composition of the weld in the stir zone confirmed the presence of intermetallic compounds at the boundary of two alloys.
3.4 Particle distribution Uniform distribution of particles in the weldments increased the pinning effects and consequently increasing the weld strength [27]. In the case of using reinforcement particles in FSW, aggregation of nanoparticles may decrease the weld strength. In this study, the SiC distribution in the stir zone of the welded samples was examined using EDAX. Figure 9a shows the FESEM map of the stir zone of welded sample with the rotational speed of 710 rpm and traverse speed of 22.4 mm/ min. The map of SiC distribution at this zone, which obtained by EDAX is presented in Fig. 9b. A uniform particle distribution in this sample was observed. The FESEM image and SiC distribution in the stir zone of the welded sample with the same rotational speed, but traverse speed of 35.5 mm/min are shown in Fig. 9c, d, respectively. It was observed that increasing the traverse speed raised the tendency to nanoparticle aggregation at the stir zone. Figure 10 shows a larger view of the cross section of this sample (RS=710 rpm, TS= 35.5 mm/min). In this photograph, the particle aggregation in
120
250
100
200 Stress [MPa]
Fig. 11 Stress-strain curves for the a friction stir welded specimens with RS=560 rpm and TS=22.4 mm/min, b AZ31 base plate
Stress [MPa]
Int J Adv Manuf Technol
80 60 40
150 100 50
20
0
0 0
0.05 Strain
(a) the interface of aluminum and magnesium alloys was observed clearly. By comparing the SiC distribution in the samples with different rotational speed, it was discovered that increasing the tool rotational speed led to a more uniform particle distribution in the weld zone. On the other side, by increasing the tool traverse speed, the appropriate opportunity for uniform particle distribution at the stir zone was decreased and a tendency to particle aggregation was increased. 3.5 Mechanical properties In this study, the prepared welded joints were cut at different longitudinal position and the weld cross sections were examined visually. No physical defect was observed beside and within the friction stir welded zone. AZ31 magnesium alloy was located in retreating side of the weld line. The stirring action of the rotating tool pin induces the plastic flow between the base alloys [15]. Macroscopic studies show that the distribution of Al and Mg alloys was depth-dependent. Similar observation was reported by Zettler et al. on dissimilar FS welding of AZ31 to AA6040 alloys [17] and by Yan et al. on dissimilar FS welding of AZ31 to AA5052 alloys [28]. Such behavior demonstrated that the transport of plasticized materials was fairly complex, and the distribution of materials in the weld zone depended to depth [29]. In this study, tension tests were employed to study the mechanical properties of the welded samples. Three tensile tests for each welding condition were conducted according to ASTM-E08 standard. The average tensile strength of the welded joints is reported in Table 4. The ultimate tensile strength (UTS) of the FS welded specimens was reduced as compared to the base materials. This reduction can be explained by probable agglomeration of nano-SiC particles in the weld stir zone and formation of intermetallic compounds such as Al12Mg17 and Al3Mg2 in the weld zone. No direct relation between the weld stir zone grain size and its strength was observed which can be explained by
0.1
0
0.2 Strain
0.4
(b) the significant effects of these two mentioned phenomena. It was observed that the weld joint strength was increased by decreasing the welding traverse speed. The maximum UTS about 106 MPa was obtained for the specimens with RS= 560 rpm and TS=22.4 mm/min. Figure 11 shows the stress– strain curves of the base metal with less strength(AZ31) and the friction stir welded specimens with highest strength (RS= 560 rpm and TS=22.4 mm/min). Formation of hard intermetallic phases decreased the weld tensile strength. Experimental tension test exhibited that the welded samples broke at small strains with the typical behavior exhibited by the brittle materials. Similar results were observed by Simoncini et al. on dissimilar friction stir welding of AZ31 to AA5754 [15]. Figure 12 shows the FESEM fracture surface image of the welded specimen obtained at 560 rpm and 22.4 mm/min. Quasi-cleavage fractured surfaces observed in this figure were in consistent with the brittle behavior of the FS welded specimens. Similar fractured surfaces were observed for the other samples.
Fig. 12 FESEM fracture surface image of FS welded sample with RS= 560 rpm, TS=22.4 mm/min
Int J Adv Manuf Technol
4 Conclusion Dissimilar friction stir welding of 7075 aluminum alloy to AZ31 magnesium alloy using SiC nanoparticles was successfully accomplished in this study. A new groove type for embedding the powder without particle scattering during the welding process was proposed. It was observed that in addition to dynamic recrystallization and annealing, pinning had a significant effect on the weld properties. Meanwhile, it was observed that the formation of intermetallic compounds at the weld zone was another influential factor on the weld quality. The results of this study are summarized as follows: – –
–
– –
–
For promoting the mixing of dissimilar alloys at the stir zone, higher tool rotational speed and lower tool traverse speed were more efficient. More dynamic recrystallization and uniform particle distribution at higher tool rotational speed decreased the weld grain size. A fine and uniform grain with average size equal to 4.36 μm was obtained at rotational speed of 560 rpm and traverse speed of 22.4 mm/min. Unlike to common rules, it was observed that the weld grain size was increased at higher tool traverse speed due to nonuniform particle distribution and consequently lower pinning effect. Microstructure studies proved that effect of pinning mechanism on the grain size was more powerful than the annealing and recrystallization mechanisms. Formation of hard and brittle intermetallic phases decreased the ductility and tensile strength of the welded joint in comparison to the base materials. The maximum UTS of about 106 MPa was obtained at rotational speed of 560 rpm and traverse speed of 22.4 mm/min. No direct relation between the weld stir zone grain size and its strength was observed which can be explained by the dominant effects of intermetalic compound and nanoparticle agglomeration on the joint strength.
Acknowledgments The authors are grateful for the support of the Iran National Science Foundation (INSF) in Project No. 9100812.
4.
5.
6.
7. 8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
References 1.
2.
3.
Nourollahi GA, Farahani M, Babakhani A, Mirjavadi SS (2013) Compressive deformation behavior modeling of AZ31 magnesium alloy at elevated temperature considering the strain effect. Mater Res 16(6):1309–1314 Liu L, Ren D, Liu F (2014) A review of dissimilar welding techniques for magnesium alloys to aluminum alloys. Mater (Basel) 7(5):3735–3757 D. Akbari, M. Farahani, and N. Soltani, “Effects of the weld groove shape and geometry on residual stresses in dissimilar butt-welded pipes,” J. Strain Anal. Eng. Des., vol. 47, no. 2, pp. 73–82, 2012. Strain Anal
19.
20.
21.
S. H. Zargar, M. Farahani, M. Besharati Givi, “Numerical and experimental investigation on the effects of submerged arc welding sequence on the residual distortion of the fillet welded plates,” P I Mech Eng B-J Eng, In Press, 2015, Sattari-Far I, Farahani M (2009) Effect of the weld groove shape and pass number on residual stresses in butt-welded pipes. Int J Press Vessel Pip 86(11):723–731 Farahani M, Sattari-Far I, Akbari D, Alderliesten R (2013) Effect of residual stresses on crack behaviour in single edge bending specimens”. Fatigue Fract Eng Mater 36:115–126 Farahani M, Sattari-Far I (2011) Effects of residual stresses on crack-tip constraints. Sci Iran B 18(6):1267–1276 Farahani M, Sattari-Far I, Akbari D, Alderliesten R (2012) Numerical and experimental investigations of effects of residual stresses on crack behavior in Aluminum 6082-T6. P I Mech Eng C-J Mech 226:2178–2191 M. Sabokrou, H. Hashemi, M. Farahani, “Experimental study of weld microstructure properties in assembling of natural gas transmission pipeline”, P I Mech Eng B-J Eng, In Press, 2015. H. Mohammadzadeh Jamalian, M. Farahani, M. K. Besharati Givi, M. Aghaei Vafaei. Study on the effects of friction stir welding process parameters on the microstructure and mechanical properties of 5086-H34 aluminum welded joints. Int J Adv Manuf Technol, In Press, 2015. A. A. M. Silva, E. Arruti, G. Janeiro, E. Aldanondo, P. Alvarez, a. Echeverria, a. a. M. A. M. da Silva, E. Arruti, G. Janeiro, E. Aldanondo, P. Alvarez, and a. Echeverria, “Material flow and mechanical behaviour of dissimilar AA2024-T3 and AA7075-T6 aluminium alloys friction stir welds,” Mater. Des., vol. 32, no. 4, pp. 2021–2027, Apr. 2011 Lee W-B, Schmuecker M, Mercardo UA, Biallas G, Jung S-B (2006) Interfacial reaction in steel–aluminum joints made by friction stir welding. Scr Mater 55(4):355–358 a. Esmaeili, M. K. B. K. B. Givi, and H. R. R. Z. Rajani, “A metallurgical and mechanical study on dissimilar Friction Stir welding of aluminum 1050 to brass (CuZn30),” Mater. Sci. Eng. A, vol. 528, no. 22–23, pp. 7093–7102, Aug. 2011 Sato YS, Michiuchi M, Kokawa H, Park SHC, Michiuchi M, Kokawa H (2004) Constitutional liquation during dissimilar friction stir welding of Al and Mg alloys. Scr Mater 50(9):1233–1236 Simoncini M, Forcellese A, Simoncini M, Forcellese A (2012) “Effect of the welding parameters and tool configuration on microand macro-mechanical properties of similar and dissimilar FSWed joints in AA5754 and AZ31 thin sheets. Mater Des 41:50–60 Mofid MA, Ghaini FM (2012) The effect of water cooling during dissimilar friction stir welding of Al alloy to Mg alloy. Mater Des 36:161–167 Zettler R, da Silva AAM, Rodrigues S, Blanco A, dos Santos JF (2006) Dissimilar Al to Mg alloy friction stir welds. Adv Eng Mater 8(5):415–421 M. a. Mofid, a. Abdollah-Zadeh, and C. H. Gür, “Investigating the formation of intermetallic compounds during friction stir welding of magnesium alloy to aluminum alloy in air and under liquid nitrogen,” Int. J. Adv. Manuf. Technol., vol. 71, no. 5–8, pp. 1493– 1499, 2014 X. J. Cao and M. Jahazi, “Friction stir welding of dissimilar AA 2024-T3 to AZ31B-H24 Alloys,” in Materials Science Forum, 2010, vol. 638, pp. 3661–3666 P. Abachi, a. H. H. Kokabi, M. Azizieh, a. H. H. Kokabi, and P. Abachi, “Effect of rotational speed and probe profile on microstructure and hardness of AZ31/Al2O3 nanocomposites fabricated by friction stir processing,” Mater. Des., vol. 32, no. 4, pp. 2034–2041, Apr. 2011 Barmouz M, Asadi P, Givi MKB, Taherishargh M, Besharati Givi MKK, Taherishargh M (2011) Investigation of mechanical
Int J Adv Manuf Technol
22.
23.
24. 25.
properties of Cu/SiC composite fabricated by FSP: effect of SiC particles’ size and volume fraction. Mater Sci Eng A 528(3):1740– 1749 a. Dolatkhah, P. Golbabaei, M. K. Besharati Givi, F. Molaiekiya, M. K. B. Givi, and F. Molaiekiya, “Investigating effects of process parameters on microstructural and mechanical properties of Al5052/SiC metal matrix composite fabricated via friction stir processing,” Mater. Des., vol. 37, pp. 458–464, May 2012. Sun YF, Fujii H (2011) The effect of SiC particles on the microstructure and mechanical properties of friction stir welded pure copper joints. Mater Sci Eng A 528(16):5470–5475 Mishra RSR, Ma ZY (2005) Friction stir welding and processing. Mater Sci Eng R Rep 50(1):1–78 Morisada Y, Fujii H, Nagaoka T, Fukusumi M (2006) Effect of friction stir processing with SiC particles on microstructure and hardness of AZ31. Mater Sci Eng A 433(1–2):50–54
26.
27.
28.
29.
Yan J, Xu Z, Li Z, Li L, Yang S (2005) Microstructure characteristics and performance of dissimilar welds between magnesium alloy and aluminum formed by friction stirring. Scr Mater 53(5):585–589 Bahrami M, Dehghani K, Besharati Givi MK (2014) A novel approach to develop aluminum matrix nano-composite employing friction stir welding technique. Mater Des 53: 217–225 Yan Y, Zhang D, Qiu C, Zhang W, Yong YAN, Zhang D, Cheng QIU, Zhang W, Yan Y, Zhang D, Qiu C, Zhang W (2010) Dissimilar friction stir welding between 5052 aluminum alloy and AZ31 magnesium alloy. Trans Nonferrous Metal Soc China 20: s619–s623 Kwon YJJ, Shigematsu I, Saito N (2008) Dissimilar friction stir welding between magnesium and aluminum alloys. Mater Lett 62(23):3827–3829
