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Experimental Study the Effect of Tool Design on the Mechanical

Properties of Bobbin Friction Stir Welded 6061-T6 Aluminum Alloy

Samir Ali Amin* Mohannad Yousif Hanna**

Alhamza Farooq Mohamed***
*,**,*** Department of Mechanical Engineering/ University of Technology

*Email:alrabiee2002@yahoo.com

** Email: mohannad_hanna@yahoo.com

***Email: alhamza88f@yahoo.com

(Received 27 September 2017; accepted 30 January 2018)

https://doi.org/10.22153/kej.2018.01.003

Abstract

Bobbin friction stir welding (BFSW) is a variant of the conventional friction stir welding (CFSW); it can weld the

upper and lower surface of the work-piece in the same pass. This technique involves the bonding of materials without

melting. In this work, the influence of tool design on the mechanical properties of welding joints of 6061-T6 aluminum

alloy with 6.25 mm thickness produced by FSW bobbin tools was investigated and the best bobbin tool design was

determined. Five different probe shapes (threaded straight cylindrical, straight cylindrical with 3 flat surfaces, straight

cylindrical with 4 flat surfaces, threaded straight cylindrical with 3 flat surface and threaded straight cylindrical with 4

flat surfaces) with various dimensions of the tool (shoulders and pin) were used to create the welding joints. The direction

of the welding process was perpendicular to the rolling direction for aluminum plates. Tensile and bending tests were

performed to select the right design of the bobbin tools, which gave superior mechanical properties of the welded zone.

The tool of straight cylindrical with four flats, 8 mm probe and 24 mm shoulders diameter gave better tensile strength

(193 MPa), elongation (6.1%), bending force (5.7 KN), and welding efficiency (65.4%) according to tensile strength.

Keywords: Bobbin FSW, Bobbin tool design, AA6061-T6, Mechanical properties.

1. Introduction

Friction stir welding (FSW) is a solid-state

bonding process feigned in 1991, at The Welding

Institute. FSW is a substitutional welding

technique to conventional fusion welding. The

joint is produced via a non-consumed refractory

cylindrical rotating tool, mechanically passed

through the material of the work-piece. The friction

between wear-resistant tool and the substrate

generates heat. Because the frictional heat is

generated, the stirred material is softened and

mixed [1]. Under the shoulder of the tool, the

material flows are like the forging operation,

whereas the flows of material surrounding the tool

probe are similar to the extrusion operation [2].

This technique is used for joining aluminum alloys,

although other materials are possible inclusive

dissimilar materials. The welding technology,

patented via Thomas et al. [3], has been used to

automotive, shipbuilding, and aerospace industries

[4].

The usage of a bobbin friction stir welding

(BFSW) tool, see figure (1), presented the

capability to outdo of the limitations faced in the

CFSW [5]. This technique uses a tool consisting of

a probe and double shoulders. The tool shoulders

contact with both the lower and upper substrate

surface. It can be referred to that the aluminum

alloy plates with higher thickness could be joined

Al-Khwarizmi

Engineering
Journal

Al-Khwarizmi Engineering Journal, Vol. 14, No.3, September, (2018)

P.P. 1- 11

Samir Ali Amin Al-Khwarizmi Engineering Journal, Vol. 14, No. 3, P.P. 1- 11 (2018)

by friction stir welding process; nevertheless, the

next information show why it’s eligible to also use

the BFSW-tool for this intent. Using double

shoulders able to balance the down forces created

via the tool with individual shoulders and so

revokes the resulted axial down force. As well, the

peril of root defect is basically removed with this

type of tool design. Due to the uniform heat input

distribution, the bobbin FSW process exhibits good

welded joints with lest distortions compared to the

CFSW process. In addition, the bobbin friction stir

welding technique could superfast the transverse

speed and raise the efficiency of the welding

process in substrate with thicker section [6].

Fig. 1. Schematic diagram of BFSW [4].

The design of a single shoulder tool (CFSW)

has been focused by numerous researches, while

the bobbin tool has had so less studies solicitude.

T. Neuman et al. [7] have reported that the tool with

threaded cylindrical probe and the tool with

threaded cylindrical probe having 3 flats enable to

create satisfying welding outcomes, since there is

no formed internal defect. The above tools were

utilized to weld AA2024-T351 with 4 mm

thickness. M. K. Sued et al. [8] investigated the

influence of probe geometry on the mechanical

properties and microstructure development of

6082-T6 aluminum alloy joining by BFSW and

developed a model relating the basic physics to the

manufacturing process in FSW bobbin-tool. W. M.

Thomas et al. [9] notified complete permeation

BFS welded joints, free of penetration shortage,

and root flaws. For bobbin tool, two shoulders

supply appropriate heat generation from both the

surfaces of the substrate, and the inclusion of

reactive forces within the tool itself denotes that

compressive distortion (Squashing) of the pin does

not take place. To promote the swept soft material

volume via a tapered probe; investigators exhorted

3 flat surfaces feature to be used on the probe. This

tool geometry was applied to weld 12% chromium

alloy steel 8 mm thick, and produced a successful

good weld [10]. A tapered probe with three flats

allows to reduce the diameter of the bottom

shoulder that participates in lowering the bending

moment and torque. A lot of other researchers

studied the understanding of the influence of

welding process parameters on the material flow

characteristics, microstructure evolution and

mechanical properties of the joint line welded by

BFSW [11-15].

The aim of this paper is first to design and

manufacture a new fixed type bobbin tool, to show

the effect of changing the diameters of the pin and

shoulders of this tool, and then select the best

design of this bobbin tool depending on the

mechanical properties (elongation, tensile strength

and maximum bending force) and weld joint

quality for aluminum alloy (6061-T6) welded by

bobbin FSW.

2. Experimental Work
2.1 Selection of Material and Specimens

Preparation

In this work the base metal was aluminum alloy

AA6061-T6, which is (Al-Mg-Si) grade alloy of

6xxx series. The plate of AA6061-T6 was cut into

the desired size (200 mm x 100 mm x 6.25 mm) via

a power saw cutting machine, and the edge of the

piece was ground to secure that there is no chasm

exists between the two substrates that make the

desired butt joint design. The chemical

composition of the work-piece plate was obtained

via a spectra device available in Special Institute

for Engineering Industries (SIEI), as presented in

table (1). The mechanical properties were

performed for this plate in strength laboratory in

Mechanical Engineering Department, University

of Technology and are given in table (2).

Table 1,

Standard and actual chemical compositions of aluminum alloy 6061-T6

Wt.%

Standard[16] 0.4-0.8 < 0.7 0.15-0.4 < 0.15 0.8-1.2 0.04-0.35 < 0.0.25 < 0.7 < 0.05 Bal.

Actual 0.6 0.57 0.26 0.10 0.89 0.18 0.037 0.054 0.003 Bal.

Element

Samir Ali Amin Al-Khwarizmi Engineering Journal, Vol. 14, No. 3, P.P. 1- 11 (2018)

Table 2,

Standard and actual mechanical properties of aluminum alloy 6061-T6

Yield stress(MPa) Ultimate tensile stress(MPa) Elongation (%)

Standard Value [16] ≥ 240 ≥ 290 ≥ 10
Actual Value 244.5 295 11.5

2.2 Design and Manufacturing of Bobbin

Tools

There are two significant domains of bobbin

friction stir welding tool design: selection of tool

material and geometry (features and dimensions).

There are significant influences to the tool

pending welding: high temperature, abrasive wear

and dynamic influences. Therefore, the good

materials of the tool have the following

characteristics: good wear resistance, high

temperature strength, temper resistance and good

toughness. In the FSW of aluminum alloys, the

wear of the welding tool is not so much. Tool

materials like tool steel can be utilized for FSW [2].

Hot-work tool steel (H13) is the most ordinarily

utilized material, easy availability and

machinability, wear resistance, thermal fatigue

resistance, essentially for copper and aluminum

[17]. The tools in this work were fabricated from a

hot-work tool steel (H13).

In order to select a best design, five various

tools with probe profiles (threaded straight

cylindrical pin, straight cylindrical with three flat

surfaces, straight cylindrical with four flat surfaces,

threaded straight cylindrical with three flat surfaces

and threaded straight cylindrical with four flat

surfaces) and flat shoulders with different

diameters in all cases were utilized, see figure (2).

The bobbin friction stir welding tools were

fabricated by conventional lathe and milling

machines. The tool heat treatment comprises

heating the tool alloy to 1070°C about 30 min and

then air cooling to room temperature, followed by

two tempering steps at 550°C and 500°C,

respectively. Then, the tool was air cooled to room

temperature in each step, resulting in a hardness

about 49 HRC [18, 19]. All details of designed and

fabricated bobbin tools are given in table (3),

including pin diameter, flat side width, pitch of the

thread, shoulder diameter, feature of shoulder

surface and shoulders gap.

2.3 Welding Procedure

The substrate has to be clamped rigidly at a

predetermined location onto a fixing framework,

see figure (3). Bobbin welding is started by driving

onto the edge of the work-piece and then the work-

piece is moved against the pin. The experiments

were completed using a one pass normal to the

plate rolling direction (longitudinal). At first, slow

travel speed till plastic deformation occurs,

followed by acceleration of the welding speed to

the required speed, and then the tool moves over

the joint line at a constant travel speed. The

material in front of the rotating tool probe is

plastically distorted and stirred back to the trail

edge of the tool pin in the welding [20]. The used

welding parameters were selected according to the

information from the previous research in this field

and the practical expertise. These parameters are

given in table (4). Classic milling machine model

(FU 251) was used to complete the welding

process.

Fig. 2. a) Threaded straight cylindrical with 4 flat surfaces, b) Straight cylindrical with 4 flat surfaces, c) Threaded

straight cylindrical with 3 flat surfaces, d) Straight cylindrical with 3 flat surfaces, e) Threaded straight cylindrical

pin.

c d

a b

Samir Ali Amin Al-Khwarizmi Engineering Journal, Vol. 14, No. 3, P.P. 1- 11 (2018)

Table 3,

BFSW tools (dimensions and features)

Description

of the probe

BFSW

Tool No.

diameter

(d) (mm)

Flat side

width(mm)

Pitch of

thread

(mm)

Shoulder

Diameter

(D)(mm)

Feature

shoulder

Gap of

shoulders

(mm)

Straight threaded

cylindrical

BT-1 10 _____ 1.5 20

(2d)

Flat 6.25

Straight threaded

cylindrical

BT-2 10 _____ 1 20

(2d)

Flat 6.25

Straight cylindrical +

3 flats

BT-3 10 0.67 _____ 20

(2d)

Flat 6.25

Straight cylindrical +

4 flats

BT-4 10 0.67 _____ 20

(2d)

Flat 6.25

Straight threaded

cylindrical+ 3 flats

BT-5 10 0.67 1 20

(2d)

Flat 6.25

Straight threaded

cylindrical+ 4 flats

BT-6 10 0.67 1 20

(2d)

Flat 6.25

Straight threaded

cylindrical

BT-7 8 _____ 1 16

(2d)

Flat 6.25

Straight cylindrical +

3 flats

BT-8 8 0.5 _____ 16

(2d)

Flat 6.25

Straight cylindrical +

4 flats

BT-9 8 0.5 _____ 16

(2d)

Flat 6.25

Straight threaded

cylindrical+ 3 flats

BT-10 8 0.5 1 16

(2d)

Flat 6.25

Straight threaded

cylindrical+ 4 flats

BT-11 8 0.5 1 16

(2d)

Flat 6.25

Straight threaded

cylindrical

BT-12 12 _____ 1.5 24

(2d)

Flat 6.25

Straight cylindrical +

3 flats

BT-13 12 0.8 _____ 24

(2d)

Flat 6.25

Straight cylindrical +

4 flats

BT-14 12 0.8

_____ 24

(2d)

Flat 6.25

Straight threaded

cylindrical+ 3 flats

BT-15 12 0.8 1.5 24

(2d)

Flat 6.25

Straight threaded

cylindrical+ 4 flats

BT-16 12 0.8 1.5 24

(2d)

Flat 6.25

Straight cylindrical +

4 flats

BT-17 8 0.5 _____ 20

(2.5d)

Flat 6.25

Straight cylindrical +

4 flats

BT-18 10 0.67 _____ 25

(2.5d)

Flat 6.25

Straight cylindrical +

4 flats

BT-19 12 0.8

_____

(2.5d)

Flat 6.25

Straight cylindrical +

4 flats

BT-20 8 0.5 _____ 24

(3d)

Flat 6.25

Straight cylindrical +

4 flats

BT-21 8 0.5 _____ 24

(3d)

Flat 6.4

Straight cylindrical +

4 flats

BT-22 8 0.5 _____ 24

(3d)

Flat 6.1

Straight threaded

cylindrical+ 3 flats

BT-23 8 0.5 1 24

(3d)

Flat 6.25

Samir Ali Amin Al-Khwarizmi Engineering Journal, Vol. 14, No. 3, P.P. 1- 11 (2018)

Fig. 3. Fixing framework.

Table 4,

Used Bobbin friction stir welding process

parameters

Tool rotational speed (spindle speed)

(rpm)

560

Welding speed (travel speed)

(mm/min)

Dwell speed

(mm/min)

manual

Dwell time

(s)

2.4 Mechanical Tests

Tensile test was done on specimens possessed

in direction normal to the joint line to define the

tensile properties of the joints for all welding

experiments. The form and dimensions of the

longitudinal tensile specimens according to the

standard (ASTM-E8) are presented in figure (4.a).

Tensile experiments were done at 1 mm/min

loading rate at room temperature using a

computerized universal testing machine (Hydraulic

Tunis Olsen). Then, the average value of three

tested samples was taken for determining the

elongation and ultimate tensile strength of each

joint. Three point bending test was done to obtain

the maximum bending force of the joints. The form

and dimensions of the longitudinal bending sample

according to the standard (ASTM-E190) are

presented in figure (4.b). The bending test was

done at constant loading rate (5 mm/min) at room

temperature by a universal testing machine

(Hydraulic LARYEE testing machine).

Fig. 4. a) Tensile test specimen (all dimensions in

mm) (ASTM-E8), b) Bending test specimen (all

dimensions in mm) (ASTM-E190M) .

3. Experimental Results and Discussion
3.1 Visual Inspections

The visual inspection consequences are

presented in Fig. 5. These exhibit the bottom and

top of each joint. Some of the welded joint had a

good appearance, while other welds appeared

various flaws, involving open tunnel/void,

excessive flash, cutting effects and incomplete

joining.

1) Open tunnel and excessive flash (figures 5a and
5b): This phenomenon has not been discussed and

identified its causes in the previous literature in

large active area, but it can be explicated as

follows. The distribution of vertical material flow

was asymmetry that was evident in threaded

cylindrical probe. This distribution had

overflowing material on the upper substrate

surface, and weld bead thinning on the lower

surface. The probe threads might result much

material motion toward the single surface. The

potential of threaded profile potential resulting

extravagant flux of vertical material has previously

been specified [21]. The clockwise rotation of the

tool, which is the state of present research, also the

stationary vertical location of the bobbin tool

prohibited the down movement of the tool. In this

state, the threads existence on the probe draws up

the work-piece. Thus, the swept material from the

retreating side faces the soft material of the

advancing side, and a complicated blending type

Samir Ali Amin Al-Khwarizmi Engineering Journal, Vol. 14, No. 3, P.P. 1- 11 (2018)

engenders, see figure (6). The retreating side

shown in figure (7A) is pushed vertically up toward

the advancing side. Therefore, the top site of the

advancing side (figure 7B) is firstly filled. The

smaller threads pitch will possess minimal helix

angle, thus minimizing the transportation of

vertical material and the flash defect, see figure (7).

2) Cutting effect (figure 5c): In this state, the plates
were softened and cut via the bobbin tool and no

welding took place. This was occurred when the

diameter of the pin was 12 mm (about twice

thickness of substrate) BT (12-16). The reason of

this case is that the amount of heat input was not

enough. The amount of heat generated is not

significant to produce a good mixing for soft

material flow and occur a dynamic recrystallization

compared to the volume of the material was stirred.

For (BT-19) design, the welding was successful,

because the diameter of the shoulders was bigger;

this means the heat input was significant to produce

free defect welding.

3) Incomplete joints/voids/flash defect (figures 5d
to 5g): With gap's variation, there are changes in

the semblance of welding line. When the bobbin

tool (BT-21) has a gap of 6.4 mm, which is higher

than the upper allowable limit of plate thickness

(6.25 mm) due to the difficulty in filling and

coalescing the stir zone. Another case was the tool

(BT-22) having a gap of 6.1 mm. At the top surface,

there was only a slight of flash, while at the bottom

surface there was an excessive flash/ scraping and

consequent decrease in thickness.

Several welding joints were unacceptable,

because there were flash and voids in the joint line

and the other joints were incomplete. These defects

are not dependent only on the pin geometry (shape

and dimension). Other variables can cause these

defects, e.g. bad tool fabrication, substrate

condition (flatness variation), and support/clamp

setting, see figure (8).

Also, the failed outcomes possess partnership to

how explicate the acceptable welding joints. It is

submitted that the sundry influences participate to

acceptable welds. The stirred material needs to

have horizontal and vertical flow; the flow

movement produces by the tool features. Thus,

threads create vertical flow motion [21, 22] and

flats produce horizontal movement [23]. Hence, the

tools (threaded cylindrical with 3/4 flats), which

comprise these profiles, achieved properly. Tools

that own flats only, such as (straight cylindrical

with 3/4 flats), are also capable to create sound

welds. Since the used plate here was not thick, it is

suggested that the fit gap between the shoulders of

the tool and substrate thickness equips with a

vertical motion flow element of soft material. Thus,

whereas flat faces might not produce the movement

of vertical flow, these features do not counter it [8].

Fig. 5. a) Open tunnel defect/ lower surface (BT-1), b) Excessive flash defect/ upper surface (TB-1), c) Cutting

effect (BT14), d) Void defect/ upper surface (BT-21), e) Incomplete welding/ lower surface (BT-21), f) Excessive

flash defect/ lower surface (TB-22), Few flash/ upper surface (TB-22) .

d e

f g

a b

Samir Ali Amin Al-Khwarizmi Engineering Journal, Vol. 14, No. 3, P.P. 1- 11 (2018)

Fig. 6. Material motion around threaded probe.

Fig. 7. Minimizing the flash defect (BT-2) .

Fig. 8. Variation of flatness plate (BT-20) .

Fig. 9. a) Upper surface, b) Lower surface .

3.2 Destructive Inspections

After implementing the welding experiments,

the joints were visually tested and the welds with

perfect surface appearance were selected and

machined according to the standard test samples

for the mechanical testing. Mechanical tests were

conducted to define the mechanical behavior of the

weld zone and select the best probe design by the

maximum welding efficiency in terms of tensile

strength. Tensile and bending tests were done, and

the results have been classed according to the tool

probe shape. The results are listed in table (5).

From these results, the best bobbin tool design for

the investigation condition (substrate type,

thickness, and process settings) is (BT-20), which

provides superior mechanical properties, see figure

(9). Since the spindle and welding speeds used in

this work cannot be considered as optimum

parameters, so the obtained results of the

mechanical properties are not the maximum for this

bobbin tool (BT-20) design.

3.3 Effects of Used Bobbin Tool Design

Features and Dimensions on Weld Quality

The outcomes characterize specifically the

functional effects, for example, the thread on tool

probe. The following duty is to establish a

systematic explication for the causality by tool

shape and other parameters that cause weld quality

influences. These are established on the

interpretations (above) of the empirical clues

compiled in this work, and informed via the

conclusions of other research in this field.

a) Threads feature (BT1, BT6 and BT11) produces
high heat input and vertical flow movement

following the thread orientation. The result is

harmonious with pervious studies [21, 22, and 24].

However, the point of distinction in this research is

the threads on the pin cause open tunnel defect in

the advanced side on the bottom surface of the

substrate and lead to excessive flash. This effect

can be termed a drill effect as discussed above.

Samir Ali Amin Al-Khwarizmi Engineering Journal, Vol. 14, No. 3, P.P. 1- 11 (2018)

Table 5,

Results of mechanical properties tests

Notes B. F

(KN)

W. Eff.

U.T.S

(MPa)

Elongation

(%)

Tool

type

Exp. No.

d = 10 mm, D = 20 mm

(D = 2d)

Open tunnel defect ------ --------- ------- -------- BT-1 Test 1

Open tunnel defect ------ --------- ------- -------- BT-2 Test 2

Acceptable appearance 3.88 28.6 84.5 3.3 BT-3 Test 3

Acceptable appearance 4.9 35.6 105 4.1 BT-4 Test 4

Acceptable appearance 4.1 29.7 87.5 3.52 BT-5 Test 5

Acceptable appearance 2.3 25.4 75 2.7 BT-6 Test 6

d = 8 mm, D =16 mm

(D = 2d)

Open tunnel defect ------ ------- ------- -------- BT-7 Test 7

Acceptable appearance 5.5 40.8 95.5 5.15 BT-8 Test 8

Acceptable appearance 4.8 34.6 120 3.97 BT-9 Test 9

Acceptable appearance 2.5 30.2 102 3.4 BT-10 Test 10

Acceptable appearance 4.5 32.4 89 3.8 BT-11 Test 11

d = 12 mm, D = 24 mm

(D = 2d)

Open tunnel defect ------ -------- ------- -------- BT-12 Test 12

Cutting defect ------ -------- ------- -------- BT-13 Test 13

Cutting defect ------ -------- ------- -------- BT-14 Test 14

Cutting defect ------ -------- ------- -------- BT-15 Test 15

Cutting defect ------ -------- ------- -------- BT-16 Test 16

d = 8, 10 and 12 mm (respectively)

(D = 2.5 d)

Acceptable appearance 5.75 47.5 140 5.57 BT-17 Test 17

Acceptable appearance 4.7 36 106 4.3 BT-18 Test 18

Acceptable appearance 5.1 33.9 100 3.88 BT-19 Test 19

d = 8 mm, D = 24 mm

(D = 3d)

Acceptable appearance 5.7 65.4 193 6.1 BT-20 Test 20

Incomplete ------ --------- ------- -------- BT-21 Test 21

Flash (scraping) ------ --------- ------- -------- BT-22 Test 22

Acceptable appearance 5.1 45.1 133 5.45 BT-23 Test 23

b) The visual analysis denotes that the gap of the
bobbin tool effects on the welded appearance.

When the gap was bigger than the thickness of the

substrate, there were incomplete joints and voids

because of lack of strength in forging (thrust load).

When the gap was lower than thickness, the edge

of the shoulder scraped very thin layer of the

surface of the substrate that leaded to produce an

excessive flash and reduce the thickness of the

plate. Consequently, the gap between shoulders

must be equal to the thickness of the work-piece

because it is the one with superior properties,

which is harmonious with other study [4, 25].

c) In general, the bobbin tool (TB-10) created a
good weld joint compared to that was produced by

(TB-5). The reason of this is the tool (TB-10) had

smaller dimensions than (TB-10). The reduction of

strength is supposed to be on account of the amount

of area (volume of material sweeping) that was

influenced via the bobbin tool during welding

process [26]. This interpretation applies to others

tools.

d) The design of shoulders influences the
generation of heat [26]. For the thickness of plate

as used in this investigation, the needed heat

generation could readily be taken out by the two

sides of the bobbin tool features. Shoulder diameter

has significant effect to improve the welding zone

properties. The swell in the diameter of the

shoulder means the growing of the friction area and

thus increases the heat generated. Large amount of

heat input is desired to break the grain boundary in

transverse the welding through the work-piece [8].

The tunnel flaw at sample (TB-10) is elucidated

that the reduced zone of provided heat via the

smaller shoulder diamete probably resulted in

premature solidification of the welding zone. The

premature solidification and the tool dimension and

Samir Ali Amin Al-Khwarizmi Engineering Journal, Vol. 14, No. 3, P.P. 1- 11 (2018)

its influence on the flow stress stated in [27, 28, and

29]. The above reason explains the results of

welding obtained from (TB-10) and (TB-23), see

figure (10).

Fig. 10. a) Internal void (BT-10), b) Perfect cross-

section welded zone (BT-23).

4. Conclusions

The overall aim of this investigation was to

better comprehend the influence of tool geometry

(features and dimensions) on the weld joint quality

and select the best tool design for bobbin kind

friction stir welding. So, from the present wok, the

followings can be concluded:

1- Straight cylindrical probe with four flats created
a free defect weld joint for the used thin substrate

aluminum alloy 6061-T6 with superior mechanical

properties (elongation, ultimate tensile strength

and maximum bending force), resulting in a

preferable bobbin tool design in the present

investigation.

2- The dimensions of the bobbin tool (shoulders
and pin) have a significant effect on the welding

quality.

3- For the best bobbin tool design, the internal
diameter of the pin is nearly similar to the substrate

thickness, and the shoulder diameter should be

three times the pin diameter.

4- The gap between the tool shoulders must be
equal to substrate thickness.

5- The distance between tool shoulders can be
adjusted to insert a useful compression influence,

hence vertical flow movement.

6- The effects of stirring consisting of horizontal
and vertical flow movements are significant to

generate good weld quality.

5. References

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)2018( 1-11، صفحة 3د، العد14دجلة الخوارزمي الهندسية المجلم سمير علي امين

على الخواص الميكانيكية (Bobbin)دراسة تأثير تصميم عدة اللحام بالخلط االحتكاكي نوع
(T6-6061)لسبيكة المنيوم

الحمزة فاروق محمد*** مهند يوسف حنا** سمير علي أمين*
التكنولوجيةقسم الهندسة الميكانيكية/ الجامعة *،**، ***

alrabiee2002@yahoo.com :البريد االلكتروني *
mohannad_hanna@yahoo.com: البريد االلكتروني **

alhamza88f@yahoo.com :البريد اإللكتروني ***

الخالصة

، حيث يتم لحام قطعة العمل من الوجهين نفسها لطريقةل) يكون مختلف عن اللحام المتعارف علية bobbinاللحام بالخلط االحتكاكي بأداة تشبه البكرة (
. يتضمن هذا األسلوب لحام اللوحين من دون االنصهار. في هذا العمل، تم التحقق من تأثير تصميم األداة على الخواص نفسها لشوطلاالعلى و االسفل في

كذلك ،و(bobbin)الملحومة بطريقة اللحام الخلطي االحتكاكي نوع وملم) ٦٬٢٥و بسمك ( (T6-6061)الميكانيكية لوصالت اللحام لسبيكة االلمنيوم نوع
أوجه، أسطواني مستقيم ٣. خمسة أشكال مختلفة لوتد أداة اللحام (أسطواني مستقيم مسنن، أسطواني مستقيم ذو (bobbin)تحديد أفضل تصميم ألداة اللحام نوع

أوجه) وبأبعاد مختلفة لألداة ( الدبوس و األكتاف ) استخدمت ألجراء عملية ٤ستقيم مسنن ذو أوجه و أسطواني م ٣أوجه، أسطواني مستقيم مسنن ذو ٤ذو
ها ألختيار التصميم األفضل ألداة اللحام نوع ؤاللحام. أتجاه عملية اللحام كان عموديا على أتجاه الدرفلة أللواح األلمنيوم. اختبارات الشد واالنحناء تم اجرا

)bobbin٨أوجه، بقطر للوتد ( ٤ي افضل الخواص الميكانيكية لمنطقة اللحام. األداة ذات االسطواني المستقيم ذو ) والتي تعط mm) ٢٤) واالكتاف mm (
) نسبة الى مقاومة %٦٥٫٤كيلو نيوتن) وأفضل كفاءة لحام ( ٥٫٧) مع أقصى قوة انحناء (%٦٫١ميكا باسكال) وأستطالة ( ١٩٣أعطت افضل مقاومة شد (

الشد.