The Way to Connect Light Materials: Ultrasonic Spot Welding of Titanium and Magnesium Alloys

Tech 2023-07-03 22:19:55 Source: Network

Article 1 Fat Boy Research SocietyEditor | Fat Boy Research SocietyPrefaceThis study mainly explores the effects of ultrasonic spot welding on different alloys(Magnesium and titanium alloys)The impact of connections. It was found that with the increase of energy input, the strength of welded joints also increases

Article 1 Fat Boy Research Society

Editor | Fat Boy Research Society

Preface

This study mainly explores the effects of ultrasonic spot welding on different alloys(Magnesium and titanium alloys)The impact of connections. It was found that with the increase of energy input, the strength of welded joints also increases.

furthermoreThe fracture first occurs inside the magnesium alloyIt shows that the connection strength of the weld interface is very high. Although some refined banded grains were observed at the interface on the magnesium alloy side, no evidence was foundTransition layer or intermetallic composite layer.

Additionally, they found that the interface temperature exceededTemperature range of liquid magnesium alloy.,Help connect magnesium and titanium alloys.Ultrasonic spot welding.

With the development of Light metal and alloysAutomotive and Aerospace Industries,.,//,.,Al3Mg2, Al12Mg17, AlTi, AlTi3, Al3Ti.,Will affect the strength and reliability of welded joints.Connection of different light alloys.

.,,Solid phase welding or fusion welding method with added alloy components,.

/,.,,furthermore0.1%.,, and.

Experimental Results

Currently, when welding different magnesium/titanium based alloys, the main methods used areCold metal transfer welding - brazingLaser beam welding and Friction stir welding.,Ultrasonic spot welding,.

.,Al/AlMg/MgTi/TiAnd some results have been achieved on alloys of different materials such as Mg/Al and Ti/Al,Ultrasonic spot weldingEffectively reducing the generation of intermetallic compounds,And produced high-strength joints.

In addition, there are other different alloys or metals,, has already been carried outUltrasonic spot welding,.

However, so far, regarding non reactivity andThe research on the connection between mutually insoluble magnesium/titanium based alloys is very limited,Ultrasonic spot welding.

,weld seamweld seamMicrostructure.

Ultrasonic welding has been selected1.5mm thick magnesium alloy AZ31B and 1.5mm thick titanium alloy Ti6Al4V as samples,8025.,,.

During the welding process,,0.35 MPa20 kHz20m30 m200800,Interval of 100 milliseconds.

Drill a hole with a diameter of 0.5 mm on the side of the sample,,0.5.,Sandpaper to be used for welding specimens.Ti0-0.5 mm.

In order to evaluate the mechanical strength of the joint and determine the optimal connection conditions, tensile shear tests were conducted,Using a constant crosshead speed of 1 mm/minAn experiment was conducted at room temperature to measure the lap shear failure load. In order to observe the microstructure and fracture surface of the joint, aIn addition, it also usesElectron probe microanalysis for line scanning,.

According to Figure 1 (a),Magnesium/titanium based alloys use 7 different welding times,,,,600.

When the welding time is 700 milliseconds,The average failure load reached 3.8 kNHowever, when the welding time increases to 800 milliseconds, excessive thermal vibration combined effects may occur, leading to significant surface damage to the magnesium alloyCollapse and cracks.

,.,8004,.,Mg/Mg alloy joint produced by Ultrasonic welding864.2.

Figure 1a. Strength of joints (time dependent load)

According to the results of Figure 1 (b), preliminary fatigue tests were conducted under force control conditions,Load ratio is 0.2, frequency is 20 Hz,60%.

The results show that,At welding times of 600 milliseconds and 700 millisecondsThe fatigue life can exceed10 ^ 4 cycles.,Magnesium/titanium joint//.

,.,,,Connection performance of two alloys..

Figure 1b (Fatigue Life)

Figure 2 (a) shows the differences in welding time at 700 millisecondsCross section of magnesium/titanium based alloy welded jointsAlthough metallurgical reactions between magnesium and titanium are difficult to occur, good connections are achieved between magnesium alloys and titanium alloys,weld seam.

Figure 2a (Cross section of joint)

It is worth noting that,A banded grain refinement zone was observed at the central interface,2(b).300600,Microstructure.,600700weld seamMicrostructure.

Figure 2b (Cross section of joint)

23-4,30,.Observation in magnesium alloy fusion welding such as laser welding and electron beam weldingThis may be due toRapid cooling rate.grainLocal melting phenomenon of magnesium alloys.

Figure 2c (enlarged by 200x)

During the welding process,,weld seam,,.

,///,.,,grain.

Figure 2d (Element Line Scan Results)

In order to determine whether a metallurgical reaction layer has formed at the interfaceLine scanning of elements,2(d).

The occurrence of alloying elements at the Mg/Ti based metal interfaceSubstantive changesHowever, no element transformation layer was observed, and the electron backscatter diffraction results in Figure 2 (e) also showed that the magnesium alloy andTitanium alloy grains.

These results indicate that the connection between magnesium and titanium alloys occurs at the microscale, and some research reports on magnesium/titanium welding show that.

Figure 2e (Results)

According to the results of tensile shear tests, the interface fracture of magnesium/titanium alloy ultrasonic welded joints can be divided into two regions, as shown in Figure 3 (a) and (d),The top area accounts for about one-third of the joint area,.

Figure 3ab (Titanium alloy side fracture surface)

A1B1Microstructure3(b)(e),.1T1T2M1M2,MgAl,AZ31TiTi6Al4V0.9%.,Mg/Ti,Mg/Ti.

Figure 3be (Results of Fracture Surface Morphology)

The fracture surface of the extension zone is 2/3 of the bottom of the joint, which is smoother from a macro perspective. The microstructure of the A2 region shows many protrusions on the surface,,AZ31grain.

The energy dispersion spectrum results indicate that,The convex block is mainly composed of magnesium with an average content of 20% titanium,80%5-9%.Magnesium alloy side smooth zone.

These results indicate that,The welded joints of different Mg/Ti based alloys still have high connection strength in the fracture extension zone.,.

The aluminum content on the fracture surface of the magnesium side and the titanium side is different, and in the smooth area of the titanium sideAluminum content up to 8.91%,AZ31T6Al4V.

Figure 3cf (fracture surface)

And in the smooth area on the magnesium sideAluminum content decreased to 1.67%, even lower thanAluminum content of basic magnesium alloy AZ31This chemical composition analysis provides two explanations:

During the welding process,Aluminum through reactionweld seam,Mg/Ti.

,, and,XEBSD analysis did not reveal the presence of new phases on the fracture surface, possibly because the reaction layer is too thinX-ray diffraction cannot detect.

Friction through ultrasonic vibrationHeat the Mg/Ti interface to a certain temperature,.

During the welding process,weld seam,Temperature measurement requiredThe temperature measurement device is shown in Figure 4 (a),weld seam0-0.5mm.

Figure 4a (Welding Interface Temperature)

When the welding time increases to 700 and 800 milliseconds,515C563C.

Ultrasonic welding is a representative solid phase welding method,.

Figure 4b (Measurement Data)

For example, published measurement and simulation results indicate that when welding aluminum alloysweld seam500C,,,/440C.

,563C,Mg/Al437C.,AZ31559.2C.,,.

,(628.7C),4,/.

Figure 4c (Scanning Calorimetry Results)

Conclusion

,,weld seam,weld seam.

Compared to frictional heating, the degree of plastic deformation is much smaller,.Mg/TiMgMicrostructure,.

Aluminum plays a role in Mg/Ti alloy connectionsPromotional effect,,The presence of aluminum not only reduces the temperature of grain boundary liquefaction,..

At this interface temperature, only the grain boundaries of magnesium alloy have reachedLiquid eutectic temperature,AZ31,,The grain boundary forms a partially melted region after remelting.

When the welded joint passes throughTensile shear fracture,grainSeparation from some melt zones and retentionOn the surface of titanium alloy,,Temperature close to complete liquefaction of magnesium alloy,.

,Ultrasonic spot welding for connecting different Mg/Ti alloys,,,Thereby significantly reducing the failure load.

The average maximum failure load and failure strength are close toWelding strength of magnesium alloys,grain.

However, YuanIsoline scanning,The fracture first occurs inside the magnesium alloy,weld seam.

Measurement interface,,/Acting as a bridge with high-strength connections.

Disclaimer: The content of this article is sourced from the internet. The copyright of the text, images, and other materials belongs to the original author. The platform reprints the materials for the purpose of conveying more information. The content of the article is for reference and learning only, and should not be used for commercial purposes. If it infringes on your legitimate rights and interests, please contact us promptly and we will handle it as soon as possible! We respect copyright and are committed to protecting it. Thank you for sharing.(Email:[email protected])

Mobile advertising space rental

Tag: The Way to Connect Light Materials Ultrasonic Spot Welding