<p>This study presents an elementary analysis to determine the effect of tool offsetting (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">${T}_{\text{off}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>T</mi> <mtext>off</mtext> </msub> </math></EquationSource> </InlineEquation>) and material position (<InlineEquation ID="IEq2"> <EquationSource Format="TEX">${M}_{\text{position}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>M</mi> <mtext>position</mtext> </msub> </math></EquationSource> </InlineEquation>) during friction stir welding (FSW) of CuZn40 and AA1100 in the open air (OAFSW) and underwater (UWFSW) environment. The suppression of FSW tool torque input (<InlineEquation ID="IEq3"> <EquationSource Format="TEX">$\tau$</EquationSource> <EquationSource Format="MATHML"><math> <mi>τ</mi> </math></EquationSource> </InlineEquation>), along with improved joint quality, is the main objective of this research. Mechanical and metallurgical characterization test results show that UWFSW improves the joint hardness and inhibits the defect and intermetallic compound (IMCs) formation. Enhancement in the joint hardness increases vertical force (<InlineEquation ID="IEq4"> <EquationSource Format="TEX">${F}_{\text{Z}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>F</mi> <mtext>Z</mtext> </msub> </math></EquationSource> </InlineEquation>) and <InlineEquation ID="IEq5"> <EquationSource Format="TEX">$\tau$</EquationSource> <EquationSource Format="MATHML"><math> <mi>τ</mi> </math></EquationSource> </InlineEquation> input during UWFSW. In addition, the FSW processing parameters (FSW-PP) also affect <InlineEquation ID="IEq6"> <EquationSource Format="TEX">${F}_{\text{Z}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>F</mi> <mtext>Z</mtext> </msub> </math></EquationSource> </InlineEquation> and <InlineEquation ID="IEq7"> <EquationSource Format="TEX">$\tau$</EquationSource> <EquationSource Format="MATHML"><math> <mi>τ</mi> </math></EquationSource> </InlineEquation> input. Tool shoulder plunge depth (<InlineEquation ID="IEq8"> <EquationSource Format="TEX">${SP}_{\text{D}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mrow> <mi mathvariant="italic">SP</mi> </mrow> <mtext>D</mtext> </msub> </math></EquationSource> </InlineEquation>), rotational speed (<InlineEquation ID="IEq9"> <EquationSource Format="TEX">$\omega$</EquationSource> <EquationSource Format="MATHML"><math> <mi>ω</mi> </math></EquationSource> </InlineEquation>), <InlineEquation ID="IEq10"> <EquationSource Format="TEX">${T}_{\text{off}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>T</mi> <mtext>off</mtext> </msub> </math></EquationSource> </InlineEquation>, and <InlineEquation ID="IEq11"> <EquationSource Format="TEX">${M}_{\text{position}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>M</mi> <mtext>position</mtext> </msub> </math></EquationSource> </InlineEquation> significantly influenced the <InlineEquation ID="IEq12"> <EquationSource Format="TEX">${F}_{\text{Z}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>F</mi> <mtext>Z</mtext> </msub> </math></EquationSource> </InlineEquation>, <InlineEquation ID="IEq13"> <EquationSource Format="TEX">$\tau$</EquationSource> <EquationSource Format="MATHML"><math> <mi>τ</mi> </math></EquationSource> </InlineEquation> input, and the quality of CuZn40-AA1100 joints. The parametric combination of <InlineEquation ID="IEq14"> <EquationSource Format="TEX">$\omega$</EquationSource> <EquationSource Format="MATHML"><math> <mi>ω</mi> </math></EquationSource> </InlineEquation> and <InlineEquation ID="IEq15"> <EquationSource Format="TEX">${SP}_{\text{D}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mrow> <mi mathvariant="italic">SP</mi> </mrow> <mtext>D</mtext> </msub> </math></EquationSource> </InlineEquation>, 1400 rpm and 0.2 mm (14,0.2), produces high-quality weld joints in both welding conditions. Electron back-scattered diffraction (EBSD) results confirmed that the percentage of high-angle boundaries and recrystallized grains was higher in UWFSW, yielding a fine grain structure. In UWFSW, at the optimum condition (14,0.2), the weld joint mean values for IMCs thickness, tensile strength, grain size, and hardness in the stirred zone (SZ) were 0.71 µm, 98 MPa, 9.07 µm, and 121.83 HV. A minor change in these values was observed by changing <InlineEquation ID="IEq16"> <EquationSource Format="TEX">${T}_{\text{off}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>T</mi> <mtext>off</mtext> </msub> </math></EquationSource> </InlineEquation> and <InlineEquation ID="IEq17"> <EquationSource Format="TEX">${M}_{\text{position}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>M</mi> <mtext>position</mtext> </msub> </math></EquationSource> </InlineEquation>. However, significant reduction in the <InlineEquation ID="IEq18"> <EquationSource Format="TEX">$\tau$</EquationSource> <EquationSource Format="MATHML"><math> <mi>τ</mi> </math></EquationSource> </InlineEquation> and tool power input (<InlineEquation ID="IEq19"> <EquationSource Format="TEX">${P}_{\text{Tool}})$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi>P</mi> <mtext>Tool</mtext> </msub> <mrow> <mo stretchy="false">)</mo> </mrow> </mrow> </math></EquationSource> </InlineEquation> was found in UWFSW by changing <InlineEquation ID="IEq20"> <EquationSource Format="TEX">${T}_{\text{off}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>T</mi> <mtext>off</mtext> </msub> </math></EquationSource> </InlineEquation> and <InlineEquation ID="IEq21"> <EquationSource Format="TEX">${M}_{\text{position}}$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>M</mi> <mtext>position</mtext> </msub> </math></EquationSource> </InlineEquation> towards softer metal (AA1100).</p>

Enhancing metallurgical and mechanical properties with minimizing tool torque input in underwater friction stir welding of AA1100 and CuZn40 by changing tool offsetting and material position

期刊论文
发表日期：

2025年11月24日

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Surendra Kumar Lader,
Souvik Karmakar,
Mayuri Baruah,
Raj Ballav,
Gunda Yoganjaneyulu,
Vikash Murmu

摘要

This study presents an elementary analysis to determine the effect of tool offsetting ( ${T}_{\text{off}}$ $T_{off}$ ) and material position ( ${M}_{\text{position}}$ $M_{position}$ ) during friction stir welding (FSW) of CuZn40 and AA1100 in the open air (OAFSW) and underwater (UWFSW) environment. The suppression of FSW tool torque input ( $\tau$ $τ$ ), along with improved joint quality, is the main objective of this research. Mechanical and metallurgical characterization test results show that UWFSW improves the joint hardness and inhibits the defect and intermetallic compound (IMCs) formation. Enhancement in the joint hardness increases vertical force ( ${F}_{\text{Z}}$ $F_{Z}$ ) and $\tau$ $τ$ input during UWFSW. In addition, the FSW processing parameters (FSW-PP) also affect ${F}_{\text{Z}}$ $F_{Z}$ and $\tau$ $τ$ input. Tool shoulder plunge depth ( ${SP}_{\text{D}}$ ${SP}_{D}$ ), rotational speed ( $\omega$ $ω$ ), ${T}_{\text{off}}$ $T_{off}$ , and ${M}_{\text{position}}$ $M_{position}$ significantly influenced the ${F}_{\text{Z}}$ $F_{Z}$ , $\tau$ $τ$ input, and the quality of CuZn40-AA1100 joints. The parametric combination of $\omega$ $ω$ and ${SP}_{\text{D}}$ ${SP}_{D}$ , 1400 rpm and 0.2 mm (14,0.2), produces high-quality weld joints in both welding conditions. Electron back-scattered diffraction (EBSD) results confirmed that the percentage of high-angle boundaries and recrystallized grains was higher in UWFSW, yielding a fine grain structure. In UWFSW, at the optimum condition (14,0.2), the weld joint mean values for IMCs thickness, tensile strength, grain size, and hardness in the stirred zone (SZ) were 0.71 µm, 98 MPa, 9.07 µm, and 121.83 HV. A minor change in these values was observed by changing ${T}_{\text{off}}$ $T_{off}$ and ${M}_{\text{position}}$ $M_{position}$ . However, significant reduction in the $\tau$ $τ$ and tool power input ( ${P}_{\text{Tool}})$ $P_{Tool})$ was found in UWFSW by changing ${T}_{\text{off}}$ $T_{off}$ and ${M}_{\text{position}}$ $M_{position}$ towards softer metal (AA1100).