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Investigation of cold pressure welding of aluminum powder to internal surface of aluminum tube
Materials and Design 30 (2009) 723–726
Contents lists available at ScienceDirect
Materials and Design journal homepage: www.elsevier.com/locate/matdes
Investigation of cold pressure welding of aluminum powder to internal surface of aluminum tube H. Danesh Manesh *, A. Mashreghi, S. Ehtemam Haghighi, A. Khajeh Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz, Iran
a r t i c l e
i n f o
Article history: Received 12 November 2007 Accepted 8 May 2008 Available online 15 May 2008 Keywords: A. Non ferrous metal and alloys B. Powder metallurgy D. Bonding
a b s t r a c t In this study the cold pressure welding between the aluminum powder and internal surface of aluminum tube was evaluated. The aluminum powder was compacted into the aluminum tube using the punch. The bond shear strength between the green compact disc and internal surface of tube at different amount of normal pressure of compaction was investigated. The effect of pressure on the cold bonding between the green compact disc and the inner surface of aluminum tube was investigated by SEM. The results of this study indicate that the discontinuity regions at the interface of the green compact disc and the inner surface of aluminum tube decreased and the bond shear strength increased with increasing compact pressure. Ó 2008 Elsevier Ltd. All rights reserved.
1. Introduction Cold pressure welding is a solid phase welding process where bonding is established by joint plastic deformation of the metals to be bonded. Bonding is obtained when surface expansion has caused the virgin metal surfaces to be exposed on the intimate surfaces. Also the pressure has reached a value large enough to extrude these virgin materials through the cracks of the fractured covering layer establishing the contact and bonding between the opposing virgin surfaces [1-16]. It has been reported that the cold welding of metals is affected by various factors such as the amount of deformation [16–21], the metal under consideration [35], the temperature of welding [1,22], the amount of pressure [14,23], the time of welding [9,10,14], the lattice structure [35], the metal purity [5], the surface preparation [5,6,8,10,12–17,24–26], the geometry of deformation zone (shape factor) [27], and the post-heat treatment of welds [10,24,28,29]. In order to produce satisfactory metallurgical bond in cold welding, it is essential to remove the contamination layers between the surfaces of two metals to be joined [30,31]. These layers are composed of oxides, absorbed ions (ion of sulfur, phosphor and oxygen), grease, humidity and dust particles [31]. The removal of the contamination layers from surfaces of two metals is usually carried out by chemical and mechanical treatment [30–32]. During recent decades, a number of investigations have been carried out on the mechanisms of pressure welding characteristics of metals and a wide variety of behaviors has been observed [13]. The exist-
* Corresponding author. Tel./fax: +98 7112307293. E-mail address: [email protected] (H. D. Manesh). 0261-3069/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.matdes.2008.05.014
ing practice of welding in the solid has been based on four classes of hypotheses [7], that is mechanical [13], energy barrier, diffusion bonding and joint recrystallisation [33]. The mechanical hypothesis or the film theory has been the major mechanism in cold welding because of low temperature [5,7,9,13,16]. According to this theory, cold welding of metals consists of three steps: (1) Coherent fracture of surface layers resulting from extension of the interface during deformation. (2) Extrusion of underlaying surfaces through interfacial cracks from both sides of the interface under the action of normal pressure and (3) Metallic bonding between freshly created surfaces that approach to within interatomic distance [13,16]. In this study the cold pressure welding between the compacted aluminum powder and the inner surface of aluminum tube was investigated. The results of this study indicate that it can be created a suitable metallurgical bond between green compact and inner surface of tube. 2. Experimental procedures 2.1. Materials In this study annealed aluminum Al1100-O tube with inner diameter of 20 mm, wall thickness of 3 mm and height of 10 mm and pure commercial aluminum powder with round shape and mean particle size of 50 lm were used to produce test samples.
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Table 1 The specification of aluminum tubes Material
Chemical composition (wt.%)
Aluminum 1100
Al 99
Cu 0.05
Mn 0.05
Si 0.8
Zn 0.1
Yield strength (MPa)
Tensile strength (MPa)
Elongation (%)
Temper
34.5
89.6
35
0
Chemical composition and mechanical properties of aluminum tube were summarized in Table 1. 2.2. Cold pressure welding process The die was used for compaction and cold welding of aluminum powder into the inner surface of tube as shown schematically in Fig. 1. Before the compaction of aluminum powder into the aluminum tube, the inner surface of aluminum tube should be degreased by acetone solution and then scratch brushed by a spiral steel wire brush. The prepared tube was placed into the compaction die and the powder was compacted by a punch into it. In order to investigate the effects of the compaction pressure on bond shear strength between the compacted powder and the inner surface of tube, the samples were prepared by using different pressures between 100 MPa to 560 MPa with attention to compact pressure that required for compaction of aluminum powder. 2.3. Bond shear strength test The bond shear strength test method was shown in Fig. 2. In this method, the maximum load to break the joint between green compact disc and inner surface of tube was determined by using a punch with diameter equal to the inner diameter of tube and an instron universal test machine with cross head speed of 1 mm/min, (Fig. 2). Shear strength of joint was calculated by following equation:
Shear strength of joint ¼
F max Pdt
ð1Þ
where, Fmax, t and d were maximum load that required for break the joint between green compact and inner surface of tube, the green compact thickness and the green compact diameter, respectively.
Fig. 2. Schematic illustration of the bond shear strength test method that used in this study.
2.4. Microscopic investigation In order to assess the effect of pressure on the cold pressure welding between the green compact disc and the inner surface of aluminum tube, the interface of samples that produced with compaction pressures of 158 MPa, 330 MPa and 500 MPa were studied by using scanning electron microscope.
Fig. 1. Schematic illustration of the die used for cold welding of the aluminum powder and the inner surface of aluminum tube (a) before compaction and (b) after compaction.
H. Danesh Manesh et al. / Materials and Design 30 (2009) 723–726
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3. Results and discussion 3.1. Mechanisms of cold pressure welding between powder and inner surface of tube The mechanisms of cold pressure welding between aluminum powder and the inner surface of aluminum tube can be discussed according to the surface film theory [5,7,9,13,16]: breaking of the brittle surface layer of powder and the prepared inner surface of tube due to relative motion between the aluminum powder and the inner surface of aluminum tube that create the surface crack on them. By exerting an axial pressure on the surface of powder, a lateral pressure was exerted by the powder to the inner surface of aluminum tube that extruded the virgin metals through interfacial cracks, exposure of them under pressure and then establishment of metallurgical bonding between contamination-less virgin metals and the inner surface of tube. In this proposed mechanism, the relative motion and pressure between powder and inner surface of tube are major parameters for creating the cold pressure welding between them. 3.2. Effect of pressure on the bond shear strength The variation of bond shear strength of joint between the green compact and the inner surface of tube with respect to pressure was shown in Fig. 3. With attention to this figure the bond shear strength of joint increased with increasing the pressure [5,9,12– 14,16]. This behavior can be explained by surface film theory discussed in previous section. Increasing the axial pressure on the surface of the powder, the amount of powder height reduction increased. Thus relative motion between the powder and the inner
Fig. 3. The variation of the bond shear strength of green compact disc and inner surface of tube with respect to pressure.
Fig. 5. SEM images of the interface of samples that produced at different compaction pressures of (a) 158 MPa, (b) 330 MPa and (c) 500 MPa.
surface of tube increased, (Fig. 4). Therefore the scratching and fracture of surface layers of the powder and the inner surface of tube increased. According to Eq. (2), with increasing the axial pressure on the surface of the powder, the lateral pressure was exerted by the powder on the inner surface of tube increased [34]:
rl ¼ zra
Fig. 4. The variation of powder relative motion into the tube versus compaction pressure.
ð2Þ
where, ra, rl and z were the axial stress that applied on the powder by the compaction punch, the lateral stress exerted on the inner surface of tube by the powder and powder characteristics dependent constant, respectively. According to the surface film theory, either above situations was caused more amounts of surface cracks and extruded virgin metal to be exposed in joint interface. With attention to these, the bond area and therefore the bond shear strength increased with increasing pressure [5,9,12–14,16]. The effect of pressure on the cold bonding between the green compact disc and the inner surface of aluminum tube was investi-
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H. Danesh Manesh et al. / Materials and Design 30 (2009) 723–726
gated by SEM. Therefore, scanning electron microscope images of the interface of samples produced at different compaction pressures of 158 MPa, 330 MPa and 500 MPa, were shown in Fig. 5. With attention to this figure, discontinuity regions at the interface decreased with increasing the compaction pressure. So as the interface line of the samples that produced by the compaction pressure equal of 500 MPa, can not be recognized at SEM images of its, (Fig. 5C). On the other hand with decreasing the discontinuity regions at the interface, the bond shear strength between aluminum powder and inner surface of aluminum tube increased, as shown in Fig. 3. 4. Conclusion In this study, the cold pressure welding mechanisms between aluminum powder and inner surface of aluminum tube was investigated. The main results are summarized as follows: (1) The cold pressure welding mechanisms between aluminum powder and inner surface of aluminum tube consist of relative motion between aluminum powder and the inner surface of aluminum tube that caused scratching the inner surface of the aluminum tube by the aluminum powder and create the surface cracks on them. Then, virgin metals were extruded through interfacial cracks under lateral pressure due to normal pressure on the surface of the powder. Finally, the metallurgical bond was established between contamination-less virgin metals. (2) With attention to proposed mechanisms, the parameters that affect on the cold pressure welding and the bond shear strength of weld between the aluminum powder and the inner surface of aluminum tube included; relative motion between the powder and the inner surface of aluminum tube and the amount of pressure applied on powder surface. (3) By increasing the compaction pressure, the amount of relative motion between the aluminum powder and the inner surface of aluminum tube and the pressure exerted on the interface of the powder and the inner surface of aluminum tube was increased. Thus discontinuity regions at the interface decreased and the bond shear strength of joint increased with increasing the compaction pressure. References [1] Pan D, Gao K, Yu J. Cold roll-bonding of bimetallic sheets and strips. Mat Sci Tech 1989;5:934–9. [2] Forster JA, Jha S, Amatruda A. The processing and evaluation of clad metals. Jom 1993:35–8. [3] Tylecote RF. The solid phase welding of metal. London: Edward Arnold Ltd; 1968.
[4] AWS, Welding Handbook, Section 3. 5th ed. Cold Welding [chapter 50]. [5] Mohamed HA, Washburn J. Mechanism of solid state pressure welding. Weld J 1975:302–10. [6] Bay N. Cold welding: Part I, characteristic, bonding mechanisms, bond strength. Metal Construct 1986:369–72. [7] Lukaschkin ND, Borissow AP, Erlikh EI. The system analysis of metal forming technique in welding processes. J Mat Proc Tech 1997;66:264–9. [8] Yahiro A, Masui T, Yoshida T, Doi D. Development ofnonferrous clad plate and sheet by warm rolling with different temperature of materials. ISIJ Int 1991;31(6):647–54. [9] Vaidyanath LR, Nicholas MG, Milner DR. Pressure welding by rolling. Br Weld J 1959;6:13–28. [10] Butlin J, Mackay CA. Experiments on the roll-bonding of tin coatings to nonferrous substrates. Sheet Metal Ind 1979:1063–72. [11] Wu HY, Lee S, Wang JY. Solid-state bonding ofiron-base alloy, steel–brass, and aluminum alloy. J Mat Proc Tech 1998;75:173–9. [12] Zhang W, Bay N. Influence of hydrostatic pressure in cold-pressure welding. Annal CIRP 1992;41(1):293. [13] Cave JA, Williams JD. The mechanism ofcold pressure welding by rolling. J Inst of Metal 1973;101:203–7. [14] McEwan KJB, Milner DR. Pressure welding of dissimilar metals. Br Weld J 1962:406–20. [15] Wright PK, Snow DA, Tay CK. Interfacial conditions and bond strength in cold pressure welding by rolling. Metal Technol 1978:24–31. [16] Danesh Manesh H, Karimi Taheri A. Study of mechanisms of cold roll welding of aluminum alloy to steel strip. J Mater Sci Technol 2004;20(8):1064–8. [17] Zhang W, Bay N. Cold welding – experimental investigation of the surface preparation methods. Weld J 1997:326s–30s. [18] Zhang W, Bay N. Cold welding – theoretical modeling of the weld formation. Weld J 1997:417–20. [19] Tylecote RF, Howd D, Furmidge JR. The influence of surface films on the pressure welding of metals. Br Weld J 1958;5:21–38. [20] Vaidyanath LR, Milner DR. Significance of surface preparation in cold pressure welding. Br Weld J 1960;7:1–6. [21] Sherwood WC, Milner DR. The effect of vacuum machining on the cold welding of some metal. J Inst Metal 1969;97:1–5. [22] Xu DW, Liu YB, Lu Y, An J. Hot-roll-bonding of Al–Pb bearing alloy strips and hot dip aluminized steel sheets. J Mat Eng Perf 2001;10:131. [23] Tabata T, Masaki S, Azekura K. Bond criterion in cold pressure welding of aluminum. Mater Sci Technol 1989;5:377–80. [24] Nicholas NG, Milner DR. Roll bonding of aluminum. Brit Weld J 1962;9:469–75. [25] Donelan JD. Industrial practice in cold pressure welding. Br Weld J 1959;6:5–12. [26] Holmes E. Influence of relative interfacial movement and frictional restraint in cold pressure welding. Br Weld J 1959;6:29–37. [27] Karimi Taheri A, Majlessi SA. An investigation into the production ofbi-and trilayered strip by drawing through wedge-shape dies. J Mater Eng Perf 1992;2:285–91. [28] Danesh Manesh H, Karimi Taheri A. Bond strength and formability of Al clad steel sheet. J Alloy Compd 2003;361:138–43. [29] Danesh Manesh H, Karimi Taheri A. The effect of annealing treatment on mechanical properties of aluminum clad steel sheet. J Mater Des 2003;24:617–22. [30] Bay N, Zhang W. Influence of different surface preparation methods on the bond formation in cold pressure welding. In: Proceeding second European conference on joining technology. Italy, Florence; 1994. p. 379–88. [31] Clemensen C, Jalstrap O. Cold welding-influence of surface preparation on bond strength. Metal Construct 1986;18(10):625–9. [32] Thomas K. Roll welding. ASM Welding Handbook 1994;6:312–4. [33] Park JM. Recrystallization welding. Weld J 1953:209–21. [34] German RM. Powder metallurgy science. 2nd ed. Princeton/N.J.: Metal Powder Industries Federation; 1994..
Contents lists available at ScienceDirect
Materials and Design journal homepage: www.elsevier.com/locate/matdes
Investigation of cold pressure welding of aluminum powder to internal surface of aluminum tube H. Danesh Manesh *, A. Mashreghi, S. Ehtemam Haghighi, A. Khajeh Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz, Iran
a r t i c l e
i n f o
Article history: Received 12 November 2007 Accepted 8 May 2008 Available online 15 May 2008 Keywords: A. Non ferrous metal and alloys B. Powder metallurgy D. Bonding
a b s t r a c t In this study the cold pressure welding between the aluminum powder and internal surface of aluminum tube was evaluated. The aluminum powder was compacted into the aluminum tube using the punch. The bond shear strength between the green compact disc and internal surface of tube at different amount of normal pressure of compaction was investigated. The effect of pressure on the cold bonding between the green compact disc and the inner surface of aluminum tube was investigated by SEM. The results of this study indicate that the discontinuity regions at the interface of the green compact disc and the inner surface of aluminum tube decreased and the bond shear strength increased with increasing compact pressure. Ó 2008 Elsevier Ltd. All rights reserved.
1. Introduction Cold pressure welding is a solid phase welding process where bonding is established by joint plastic deformation of the metals to be bonded. Bonding is obtained when surface expansion has caused the virgin metal surfaces to be exposed on the intimate surfaces. Also the pressure has reached a value large enough to extrude these virgin materials through the cracks of the fractured covering layer establishing the contact and bonding between the opposing virgin surfaces [1-16]. It has been reported that the cold welding of metals is affected by various factors such as the amount of deformation [16–21], the metal under consideration [35], the temperature of welding [1,22], the amount of pressure [14,23], the time of welding [9,10,14], the lattice structure [35], the metal purity [5], the surface preparation [5,6,8,10,12–17,24–26], the geometry of deformation zone (shape factor) [27], and the post-heat treatment of welds [10,24,28,29]. In order to produce satisfactory metallurgical bond in cold welding, it is essential to remove the contamination layers between the surfaces of two metals to be joined [30,31]. These layers are composed of oxides, absorbed ions (ion of sulfur, phosphor and oxygen), grease, humidity and dust particles [31]. The removal of the contamination layers from surfaces of two metals is usually carried out by chemical and mechanical treatment [30–32]. During recent decades, a number of investigations have been carried out on the mechanisms of pressure welding characteristics of metals and a wide variety of behaviors has been observed [13]. The exist-
* Corresponding author. Tel./fax: +98 7112307293. E-mail address: [email protected] (H. D. Manesh). 0261-3069/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.matdes.2008.05.014
ing practice of welding in the solid has been based on four classes of hypotheses [7], that is mechanical [13], energy barrier, diffusion bonding and joint recrystallisation [33]. The mechanical hypothesis or the film theory has been the major mechanism in cold welding because of low temperature [5,7,9,13,16]. According to this theory, cold welding of metals consists of three steps: (1) Coherent fracture of surface layers resulting from extension of the interface during deformation. (2) Extrusion of underlaying surfaces through interfacial cracks from both sides of the interface under the action of normal pressure and (3) Metallic bonding between freshly created surfaces that approach to within interatomic distance [13,16]. In this study the cold pressure welding between the compacted aluminum powder and the inner surface of aluminum tube was investigated. The results of this study indicate that it can be created a suitable metallurgical bond between green compact and inner surface of tube. 2. Experimental procedures 2.1. Materials In this study annealed aluminum Al1100-O tube with inner diameter of 20 mm, wall thickness of 3 mm and height of 10 mm and pure commercial aluminum powder with round shape and mean particle size of 50 lm were used to produce test samples.
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Table 1 The specification of aluminum tubes Material
Chemical composition (wt.%)
Aluminum 1100
Al 99
Cu 0.05
Mn 0.05
Si 0.8
Zn 0.1
Yield strength (MPa)
Tensile strength (MPa)
Elongation (%)
Temper
34.5
89.6
35
0
Chemical composition and mechanical properties of aluminum tube were summarized in Table 1. 2.2. Cold pressure welding process The die was used for compaction and cold welding of aluminum powder into the inner surface of tube as shown schematically in Fig. 1. Before the compaction of aluminum powder into the aluminum tube, the inner surface of aluminum tube should be degreased by acetone solution and then scratch brushed by a spiral steel wire brush. The prepared tube was placed into the compaction die and the powder was compacted by a punch into it. In order to investigate the effects of the compaction pressure on bond shear strength between the compacted powder and the inner surface of tube, the samples were prepared by using different pressures between 100 MPa to 560 MPa with attention to compact pressure that required for compaction of aluminum powder. 2.3. Bond shear strength test The bond shear strength test method was shown in Fig. 2. In this method, the maximum load to break the joint between green compact disc and inner surface of tube was determined by using a punch with diameter equal to the inner diameter of tube and an instron universal test machine with cross head speed of 1 mm/min, (Fig. 2). Shear strength of joint was calculated by following equation:
Shear strength of joint ¼
F max Pdt
ð1Þ
where, Fmax, t and d were maximum load that required for break the joint between green compact and inner surface of tube, the green compact thickness and the green compact diameter, respectively.
Fig. 2. Schematic illustration of the bond shear strength test method that used in this study.
2.4. Microscopic investigation In order to assess the effect of pressure on the cold pressure welding between the green compact disc and the inner surface of aluminum tube, the interface of samples that produced with compaction pressures of 158 MPa, 330 MPa and 500 MPa were studied by using scanning electron microscope.
Fig. 1. Schematic illustration of the die used for cold welding of the aluminum powder and the inner surface of aluminum tube (a) before compaction and (b) after compaction.
H. Danesh Manesh et al. / Materials and Design 30 (2009) 723–726
725
3. Results and discussion 3.1. Mechanisms of cold pressure welding between powder and inner surface of tube The mechanisms of cold pressure welding between aluminum powder and the inner surface of aluminum tube can be discussed according to the surface film theory [5,7,9,13,16]: breaking of the brittle surface layer of powder and the prepared inner surface of tube due to relative motion between the aluminum powder and the inner surface of aluminum tube that create the surface crack on them. By exerting an axial pressure on the surface of powder, a lateral pressure was exerted by the powder to the inner surface of aluminum tube that extruded the virgin metals through interfacial cracks, exposure of them under pressure and then establishment of metallurgical bonding between contamination-less virgin metals and the inner surface of tube. In this proposed mechanism, the relative motion and pressure between powder and inner surface of tube are major parameters for creating the cold pressure welding between them. 3.2. Effect of pressure on the bond shear strength The variation of bond shear strength of joint between the green compact and the inner surface of tube with respect to pressure was shown in Fig. 3. With attention to this figure the bond shear strength of joint increased with increasing the pressure [5,9,12– 14,16]. This behavior can be explained by surface film theory discussed in previous section. Increasing the axial pressure on the surface of the powder, the amount of powder height reduction increased. Thus relative motion between the powder and the inner
Fig. 3. The variation of the bond shear strength of green compact disc and inner surface of tube with respect to pressure.
Fig. 5. SEM images of the interface of samples that produced at different compaction pressures of (a) 158 MPa, (b) 330 MPa and (c) 500 MPa.
surface of tube increased, (Fig. 4). Therefore the scratching and fracture of surface layers of the powder and the inner surface of tube increased. According to Eq. (2), with increasing the axial pressure on the surface of the powder, the lateral pressure was exerted by the powder on the inner surface of tube increased [34]:
rl ¼ zra
Fig. 4. The variation of powder relative motion into the tube versus compaction pressure.
ð2Þ
where, ra, rl and z were the axial stress that applied on the powder by the compaction punch, the lateral stress exerted on the inner surface of tube by the powder and powder characteristics dependent constant, respectively. According to the surface film theory, either above situations was caused more amounts of surface cracks and extruded virgin metal to be exposed in joint interface. With attention to these, the bond area and therefore the bond shear strength increased with increasing pressure [5,9,12–14,16]. The effect of pressure on the cold bonding between the green compact disc and the inner surface of aluminum tube was investi-
726
H. Danesh Manesh et al. / Materials and Design 30 (2009) 723–726
gated by SEM. Therefore, scanning electron microscope images of the interface of samples produced at different compaction pressures of 158 MPa, 330 MPa and 500 MPa, were shown in Fig. 5. With attention to this figure, discontinuity regions at the interface decreased with increasing the compaction pressure. So as the interface line of the samples that produced by the compaction pressure equal of 500 MPa, can not be recognized at SEM images of its, (Fig. 5C). On the other hand with decreasing the discontinuity regions at the interface, the bond shear strength between aluminum powder and inner surface of aluminum tube increased, as shown in Fig. 3. 4. Conclusion In this study, the cold pressure welding mechanisms between aluminum powder and inner surface of aluminum tube was investigated. The main results are summarized as follows: (1) The cold pressure welding mechanisms between aluminum powder and inner surface of aluminum tube consist of relative motion between aluminum powder and the inner surface of aluminum tube that caused scratching the inner surface of the aluminum tube by the aluminum powder and create the surface cracks on them. Then, virgin metals were extruded through interfacial cracks under lateral pressure due to normal pressure on the surface of the powder. Finally, the metallurgical bond was established between contamination-less virgin metals. (2) With attention to proposed mechanisms, the parameters that affect on the cold pressure welding and the bond shear strength of weld between the aluminum powder and the inner surface of aluminum tube included; relative motion between the powder and the inner surface of aluminum tube and the amount of pressure applied on powder surface. (3) By increasing the compaction pressure, the amount of relative motion between the aluminum powder and the inner surface of aluminum tube and the pressure exerted on the interface of the powder and the inner surface of aluminum tube was increased. Thus discontinuity regions at the interface decreased and the bond shear strength of joint increased with increasing the compaction pressure. References [1] Pan D, Gao K, Yu J. Cold roll-bonding of bimetallic sheets and strips. Mat Sci Tech 1989;5:934–9. [2] Forster JA, Jha S, Amatruda A. The processing and evaluation of clad metals. Jom 1993:35–8. [3] Tylecote RF. The solid phase welding of metal. London: Edward Arnold Ltd; 1968.
[4] AWS, Welding Handbook, Section 3. 5th ed. Cold Welding [chapter 50]. [5] Mohamed HA, Washburn J. Mechanism of solid state pressure welding. Weld J 1975:302–10. [6] Bay N. Cold welding: Part I, characteristic, bonding mechanisms, bond strength. Metal Construct 1986:369–72. [7] Lukaschkin ND, Borissow AP, Erlikh EI. The system analysis of metal forming technique in welding processes. J Mat Proc Tech 1997;66:264–9. [8] Yahiro A, Masui T, Yoshida T, Doi D. Development ofnonferrous clad plate and sheet by warm rolling with different temperature of materials. ISIJ Int 1991;31(6):647–54. [9] Vaidyanath LR, Nicholas MG, Milner DR. Pressure welding by rolling. Br Weld J 1959;6:13–28. [10] Butlin J, Mackay CA. Experiments on the roll-bonding of tin coatings to nonferrous substrates. Sheet Metal Ind 1979:1063–72. [11] Wu HY, Lee S, Wang JY. Solid-state bonding ofiron-base alloy, steel–brass, and aluminum alloy. J Mat Proc Tech 1998;75:173–9. [12] Zhang W, Bay N. Influence of hydrostatic pressure in cold-pressure welding. Annal CIRP 1992;41(1):293. [13] Cave JA, Williams JD. The mechanism ofcold pressure welding by rolling. J Inst of Metal 1973;101:203–7. [14] McEwan KJB, Milner DR. Pressure welding of dissimilar metals. Br Weld J 1962:406–20. [15] Wright PK, Snow DA, Tay CK. Interfacial conditions and bond strength in cold pressure welding by rolling. Metal Technol 1978:24–31. [16] Danesh Manesh H, Karimi Taheri A. Study of mechanisms of cold roll welding of aluminum alloy to steel strip. J Mater Sci Technol 2004;20(8):1064–8. [17] Zhang W, Bay N. Cold welding – experimental investigation of the surface preparation methods. Weld J 1997:326s–30s. [18] Zhang W, Bay N. Cold welding – theoretical modeling of the weld formation. Weld J 1997:417–20. [19] Tylecote RF, Howd D, Furmidge JR. The influence of surface films on the pressure welding of metals. Br Weld J 1958;5:21–38. [20] Vaidyanath LR, Milner DR. Significance of surface preparation in cold pressure welding. Br Weld J 1960;7:1–6. [21] Sherwood WC, Milner DR. The effect of vacuum machining on the cold welding of some metal. J Inst Metal 1969;97:1–5. [22] Xu DW, Liu YB, Lu Y, An J. Hot-roll-bonding of Al–Pb bearing alloy strips and hot dip aluminized steel sheets. J Mat Eng Perf 2001;10:131. [23] Tabata T, Masaki S, Azekura K. Bond criterion in cold pressure welding of aluminum. Mater Sci Technol 1989;5:377–80. [24] Nicholas NG, Milner DR. Roll bonding of aluminum. Brit Weld J 1962;9:469–75. [25] Donelan JD. Industrial practice in cold pressure welding. Br Weld J 1959;6:5–12. [26] Holmes E. Influence of relative interfacial movement and frictional restraint in cold pressure welding. Br Weld J 1959;6:29–37. [27] Karimi Taheri A, Majlessi SA. An investigation into the production ofbi-and trilayered strip by drawing through wedge-shape dies. J Mater Eng Perf 1992;2:285–91. [28] Danesh Manesh H, Karimi Taheri A. Bond strength and formability of Al clad steel sheet. J Alloy Compd 2003;361:138–43. [29] Danesh Manesh H, Karimi Taheri A. The effect of annealing treatment on mechanical properties of aluminum clad steel sheet. J Mater Des 2003;24:617–22. [30] Bay N, Zhang W. Influence of different surface preparation methods on the bond formation in cold pressure welding. In: Proceeding second European conference on joining technology. Italy, Florence; 1994. p. 379–88. [31] Clemensen C, Jalstrap O. Cold welding-influence of surface preparation on bond strength. Metal Construct 1986;18(10):625–9. [32] Thomas K. Roll welding. ASM Welding Handbook 1994;6:312–4. [33] Park JM. Recrystallization welding. Weld J 1953:209–21. [34] German RM. Powder metallurgy science. 2nd ed. Princeton/N.J.: Metal Powder Industries Federation; 1994..