Clad Materials

Resistance Welding Lesson Objectives When you finish this lesson you will understand: Learning Activities 1.View Slides; 2.Read Notes, 3.Listen to lecture 4.Do on-line workbook Keywords

Steel - Aluminum Cladding Cleaning Rolling a. Cold b F Post-Heating ~ 1000F

Hansen, Const of Binary Alloys McGraw-Hill, 1958

Aluminum Steel FeAl 3, Fe 2 Al 5 (Brittle) Si > 0.25% in Steel Tends to Reduce Brittle Iron- Alumindes Thus Higher Post Roll Temperatures can be employed Steel Aluminum Steel Aluminum

Oikawa et al, RSW of Steel & Al Sheet Using Insert, Science & Tech of Welding & Joining, vol4, 1999 Fe-Al Clad Material

Table of Steel and Aluminum Properties

Heat Flow in Spot Welding (Fe - Al) Steel Aluminum Fe Al Fe Al The lower MP of Aluminum Causes Rapid Nugget Growth Which Can Lead to Al Expulsion A Larger Electrode on the Al Side Might Help

Chang et al, Spot Welding Al to Steel, Practical Welding Today, May/June 1999

Steel Aluminum Fe-Al Weld

Oikawa et al, RSW of Steel & Al Sheet Using Insert, Science & Tech of Welding & Joining, vol4, 1999 Fe-Al Fe-Fe/Al-Al IMC = Fe 2 Al 5

Chang et al, Spot Welding Al to Steel, Practical Welding Today, May/June 1999

Oikawa et al, RSW of Steel & Al Sheet Using Insert, Science & Tech of Welding & Joining, vol4, 1999 Fracture Occurred on Tensile Load At the IMC Interface With Thinner Aluminum Sheet, Fracture Occurred by Nugget Pull-out

Chang et al, Spot Welding Al to Steel, Practical Welding Today, May/June 1999

Heat Flow in Spot Welding (Fe - Trans - Al) Steel Aluminum

Oikawa et al, RSW of Steel & Al Sheet Using Insert, Science & Tech of Welding & Joining, vol4, 1999 Steel Aluminum Steel Aluminum Transition Fe-Fe/Al-Al Weld

Chang et al, Spot Welding Al to Steel, Practical Welding Today, May/June 1999 Weld With 2 mm Steel

Chang et al, Spot Welding Al to Steel, Practical Welding Today, May/June MM Thick Steel (Faster Cooling) Shrinkage Voids in Al Due to Faster Cooling

Oikawa et al, RSW of Steel & Al Sheet Using Insert, Science & Tech of Welding & Joining, vol4, 1999

Chang et al, Spot Welding Al to Steel, Practical Welding Today, May/June 1999

Titanium Aluminum Aluminum - Titanium

Properties of Ti & Al

Ti-Ti Welds Aluminum High Conductivity Low Resistivity Low MP Titanium Low Conductivity High Resistivity High MP Ti melts, Heat flows to Al (melts a little because lower MP) but because of High Al Conductivity, Heat conducted to Electrodes

Watanabe, Resistance Welding of Ti/Al clad plate, Welding International, May 1996

Watanabe, Resistance Welding of Ti/Al clad plate, Welding International, May 1996

The high MP & high Resistance Ti pushes heat into the Aluminum Causing melting and expulsion along the Interface Ti-Al Welds Electrode Indented Forcing Al Expulsion Ti Al

Ti Al Ti Al Ti to Al Weld Watanabe, Resistance Welding of Ti/Al clad plate, Welding International, May 1996

Watanabe, Resistance Welding of Ti/Al clad plate, Welding International, May 1996

No Current Range Expulsion Watanabe, Resistance Welding of Ti/Al clad plate, Welding International, May 1996

Oxide film between Al & Ti prevents interdiffusion This also promotes Interfacial Failure Watanabe, Resistance Welding of Ti/Al clad plate, Welding International, May 1996

Al-Al Welds Case 1 Electrode Free to Move Case 2 Electrode Restrained

Watanabe, Resistance Welding of Ti/Al clad plate, Welding International, May 1996

No Restraint With Restraint Watanabe, Resistance Welding of Ti/Al clad plate, Welding International, May 1996

Watanabe, Resistance Welding of Ti/Al clad plate, Welding International, May 1996

Aluminum Stainless Steel Stainless Steel Clad Aluminum & Copper Copper Stainless Steel Hot Rolled