Using the orthogonal array with grey relational analysis to optimize the laser hybrid welding of a 6

986HRKimandKYLee

Table8

Weldingparameter

[A]Weldingwiretype

[B]Shieldinggas

[C]Laserpower

[D]Laserfocus

[E]Travellingspeed

[F]Weldingwirefeedrate

[G]Rootopeningtolerance

[H]Voltage

Error

TotalSumofsquare0.03760.00110.00150.09900.02770.07690.02840.02520.00390.3012ResultsoftheanalysisofvarianceDegreeoffreedom12222222Meansquare0.03760.00060.00080.04950.01380.03840.01420.0126F9.71780.14810.196612.79873.57449.93603.67323.2514Contribution(%)22.440.340.4529.568.2622.958.487.51100

Table10

Table9

Group

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

181216.81141.68231.20174.99198.45224.85223.27224.63174.77246.27241.51182.47190.64251.59256.69235.96239.36214.66TheSNratiooftheTaguchi’sDOE2217.62143.72239.69178.62205.48238.34245.25226.12183.61242.35242.53186.78180.09225.87259.32238.23214.09212.273216.52151.06235.54179.77201.25241.54237.98227.54177.89242.98239.44191.54183.57232.95254.78236.78228.45216.58SNratio(dB)46.7343.2547.4445.0046.0947.4147.4247.0945.0447.7447.6545.4345.3347.4648.2047.4947.1046.63Group12345678910111213141516

17

18ComparisonrankorderbetweengreyrelationalgradeandTaguchiSNratioRankorder1Greyrelationalanalysis111871713861016231415514912Rankorder2SNratioofTaguchiDOE111861713871016231415514912

Table11

Factor

A

B

C

D

E

F

G

HAcomparisonoftheresultsofthepreliminaryandoptimumprocessparametersWeldingparameterWeldingwiretypeShieldinggasLaserpower(kW)Laserfocus(mm)Travellingspeed(mm/s)Weldingwirefeedrate(m/min)Rootopeningtolerance(mm)Voltage(V)PreliminarysettingER4043He3.50805.7012.6

231.86–1.77OptimumsettingER4043Ar401206.50.210257.05–2.27Ultimatetensilestrength(MPa)

reflectagoodcharacteristicoftheoptimumhybrid

weldability.Similartotheresultofthegrey

relationalanalysis,experiment15hasthebest

performancecharacteristicamongthe18experi-

mentsusingtheTaguchiDOEapproach(Table9).

TheSNratiooftheTaguchidesignofexperimentis

alsolistedinTable9.Theoverallresultofthe

gradingorderisingoodagreementwitha

comparisonofbothrankingordersasshownin

Table10.

Proc.IMechEVol.222PartB:J.EngineeringManufactureFromtheabove,thefollowingoptimumprocessparametersweredeterminedfromtheL18orthogonalarray–theweldingwiretypeatlevel2,theshieldinggasatlevel2,thelaserpoweratlevel3,thelaserfocusatlevel1,thetravellingspeedatlevel2,theweldingwirefeedrateatlevel3,therootopeningtoleranceatlevel2,paringtheresultslistedinTable11,theweldingperformancecharacter-isticsoftheoptimumsettingarefoundtobemuchhigherthanthepreliminarysettingslistedinTable3.JEM1070ÓIMechE2008