Solid-State Welding Process

Presented By:Abdullah Mansoor-42Ahmed Ali Zafar-66Waleed Raza-52

Abu-Bakr-64

Contents

Welding Solid State Welding Cold Welding Forge Welding Ultrasonic Welding Diffusion Welding Explosive Welding

Welding Welding is a material joining

process in which two or more metals are joined at their contacting surface by applying the suitable pressure or heat.

Many welding process accomplished by heat alone with no pressure applied.

Some other process accomplished by pressure alone no external heat supplied; other accomplished both heat and pressure.

Solid State Welding:

A welding process in which coalescence takes place at temperatures below the melting point of the metals being joined and without use of a brazing filler metal.

Sometimes this is accomplished through the use of pressure.

Weld (bonding) is free from microstructure defects .

Dissimilar metals may be joined .

Forge Welding (FOW)

Cold Welding (CW)

Explosive Welding (EXW)

Diffusion Welding (DFW)

Ultrasonic Welding (USW)

Cold Welding Pressure is applied to the

workpieces through dies or rolls at room temperature.

Preferably both work pieces should be ductile

The work pieces should cleaned thoroughly

Best bond strength occurs with two similar metals.

Aluminum alloys, Copper alloys, low carbon steels, Nickel alloys, and other ductile metals may be welded by Cold Welding.

Fig: The roll bonding or cladding process

Advantages of cold welding: No heat is required Optimum weld seam quality High accuracy of workpiece material Dissimilar metals can be joined by cold

welding.

Disadvantage:o High pressure is required.o Metal to be welded must be ductile.o Contact surface must be clean.

Forge welding:

Forge welding is process in which components to be joined are heated to hot temperature and then forged together by hammer.

The process is one of the simplest method of joining used in ancient times.

Advantages of Forge Welding: Good weld quality may be obtained. Parts of intecrate shap can be welded.

No filler material use during welding.Disadvantages: Slow welding process. High operational skills are required. Only low carbon steel may be welded.

Ultrasonic Welding

Surfaces of the two components are subjected to a static forces and oscillating shearing force

Produces a strong, solid-state bond

Versatile and reliable for joining metals

Advantages of Ultrasonic welding Dissimilar metals may be joined. High quality weld is obtained. Very low deformation of work piece surfaces. Moderate level skills are enough. This process may be integrated in automated

production line.

Disadvantage: Only small and thin parts may be welded. Work piece may be bond to anvil. Work pieces and equipment may be fatigue due to

reciprocating loads of ultrasonic vibration.

Diffusion Welding: Pressure is applied to two different workpieces with carefully

cleaned surfaces and at elevated temperature of material below the melting points of metals.

Bonding of material is a result of mutual diffusion of thier atoms.

Diffusion welding can be joined disimliar metals as compare to others welding processes.

▪ Steel to tungstun.▪ Steel to noibium.▪ Steelness Steel to Titanium.▪ Gold to copper alloys.

Advantages of diffusion welding: Disimliar metals canbe joined. Welding is obtained at high quality. No limitations in the thickness of workpiece.

Disadvantages: Time consuming process with low productivity. Relatively high initial invesments in equipement. The meeting surfaces must be fitted to each other. Very thorough surface prepration to piror welding process.

Explosive Welding: Processin which welded parts are metalluragically bonded as

a result of obique impact pressure exerted on them by controlled detonation of an explosive charge.

The maximum detonation velocity is about 120% of the material sonic velocity.

Most of commercial metals and alloys may be bonded by explosive welding.

Disimlar metals may be joined which are following: Copper to steel Nickal to steel Aluminium to steel Titanium to steel Tungstun to steel

Advantages of Explosive Welding: Good bond strength achieved. Ehanced mechanical properties by joining the metals. Extremely big surface can be join. Broad range of thicknesses can be explosively clad

joint. Metal can be created on heat-treated metals with no

affecting their microstructures.

Disadvantages: Brittle material cannot procced. Only simple parts may be bonded,plates,clyinders; Thickness of flyer plate is limited-(63mm). Safety and security aspects of storage and explosives.