Que2.17. citation advantages, disadvantages and operations of brazing. Answer Advantages of Brazing 1. The main advantage of brazing process is joining of different essence and thin sections. 2. Cast and wrought material can be joined fluently. 3. Metallurgical parcels of the base material aren’t seriously distributed. 4. Assemblies can be brazed in a stress free condition. 5. Little or no finishing is needed by the brazed joints. Disadvantages of Brazing 1. It requires tightly sleeping corridor and proper cleaning. 2. Joints aren’t successful at elevated temperature. 3. Colour of the padding essence may not match that of the base essence. 4. High degree of skill is needed. Applications of Brazing 1. corridor of bike similar as frames and skirtings. 2. Pipe joints subordinated to climate. 3. Exhaust pipe in motor machine. 4. Nipples and unions of mild sword and bobby
tubing. Que2.18. What’s soldering? Explain colorful styles of soldering. citation advantages and operations of it. Answer Soldering 1. Soldering is defined as a essence joining process wherein coalescence is produced by hotting
the face to be common to a suitable temperature and melting the padding essence which is a fusible amalgamation called solder whose melting point is below 427 °C. 2. Soldering operation is performed by bringing molten solder in contact with the preheated shells and hotting
the common area to a good wetting temperature about 55 to 80 °C above the melting point of soldering amalgamation. 3. Solder is also left to cool and indurate as snappily as possible to avoid development of internal cracks in the joint. 4. Due to molecular magnet face motes of solder enter within the parent essence motes and form a strong bond. styles of Soldering Torch Soldering Method 1. A arsonist is used to supply heat which is the fast and protean process of heating. 2. Soldering firebugs are available in different design, for illustration, gasoline blow arsonist, oxy- acetylene soldering arsonistetc. 3. These types of firebugs insure a clean honey to heat the shells to be soldered, heat of honey is fluently malleable. 4. This process of soldering finds expansive use in refrigeration and air exertion shops, erecting up of irregular shells to get a finished face threaded connections in plumbing are being replaced by soldering. ii. Dip Bath system 1. In this type of soldering system, solder is melted in a pot and defended against atmospheric impurity by using a hood or cover on the pot or by furnishing a chemical content by pulverized watercolor. 2. The workpiece is first dipped in the flux bath and latterly in the solder bath. 3. The object soldered with this system are needed to be gutted before they are carpeted with flux and soldered as the humidity present on the workpiece may produce instant high temperature brume leading to the explosion of bath. iii. Wave Soldering Method 1. This is an automatic process of soldering used for the manufacturing of published circuit boards wherein the factors are passed over a surge of molten solder. 2. All factors of the circuit are clicked in one quick operation as the molten solder is pumped vertically overhead through a narrow niche forming a steady surge. 3. This way the dynamic movement of the solder across the work face improves melting, minimize heat deformation performing in an oxide free bright face of solder. Advantages of Soldering 1. Low investment of cost. 2. Simplicity and stinginess of the outfit. 3. Properties of parent essence aren’t affected due to low operating temperature. 4. Good and effective sealing in fabrication as compared to other process like engaging, spot welding and bolts. Applications of Soldering 1. Connections in wireless set, television sets, and wiring joints in electrical connections, batteryetc. 2. Drain water gutters and pipes. 3. Radiator brass tube for motor auto. 4. Bobby tubing carrying liquid energy, gas or air used on machine. Que2.19. What’s braze welding? Give advantages, disadvantages and operations of braze welding. Answer Braze Welding 1. Braze welding is a system of welding whereby a groove, fillet, draw or niche weld is made using a non ferrous padding essence having a melting point below that of the base essence but above 427 °C. 2. The padding essence isn’t distributed in the joint by capillary magnet. 3. Citation welding doesn’t mean the welding of citation, but rather it is welding using a citation padding rod. Advantages of Braze Welding 1. Braze welding associate lower energy consumption and advanced welding pets. 2. Different essence may be joined by braze welding. 3. The weld deposit is fairly soft and ductile, furnishing machinability and low residual stresses. 4. Joints with good strength and generous fillets can be produced, 5. Brittle essence(e.g., argentine cast iron) can be joined without important preheat. Disadvantages of Braze Welding 1. Braze welded joints aren’t satisfactory for service at over about 260 °C nor for dynamic loads of about 1000 kg/ cm2 or further. 2. Joints are subordinated to galvanic erosion and to discriminational chemical attack. 3. The brazing padding essence colour may not match with that of the base essence. Applications of Braze Welding 1. Braze welding may be employed for similar fabrications as essence cabinetwork, bikes, motorcars, refrigerators and ménage appliances. Que2.21. Explain ray ray welding with the help of illustration. What’s the principle of a ray generation? Answer Laser Beam Welding 1. Ray ray welding is performed by fastening the coherent monochromic light ray emitted by the ray source onto the essence corridor which are to be welded by face heating and thermal conduction through the essence. 2. There are two types of spotlights used in solid state spotlights, for illustration ruby ray and gas ray. 3. The ray demitasse( Ruby) is in the form of a cylinder, the ends being flat and resemblant to a high degree of delicacy and silvered to give glass reflecting shells. 4. There’s a small orifice on the axis of the demitasse, through the glass at the affair end. 5. When the demitasse is pumped with high intensity white light from a xenon or krypton beacon, the Cr ions in the demitasse get agitated. 6. The agitated ions retain further energy and some of it’s given as a red fluorescent light. 7. This light is reflected backward and forward in the demitasse between the two ends, striking further Cr ions on the path. 8. These ions affected by the collisions are caused to emit their share of red light instigative further and further Cr ions, until the number of collisions is high enough to beget a burst of red light through the small orifice in the glass at the affair end of the demitasse. 9. The ray produced is extremely narrow and can be concentrated to a leg point area by an optic lens. Principle of Generation of Laser Beam 1. In this, capacitor bank stores electrical energy. 2. It’s charged by a high voltage power force. 3. When subordinated to electrical discharge from the capacitors, xenon transforms a high proportion of the electrical energy into white light flashes. 4. As the ruby is exposed to the violent light flashes, the chromium tittles of the demitasse are agitated and pumped to a high energy position. 5. These chromium tittles incontinently drop to an intermediate energy position with the elaboration of heat, and ultimately drop back to their original state with the elaboration of a separate volume of radiation in the form of red fluorescent light. Que2.22. Explain how different process parameter influence ray ray welding. Answer Different process parameter influence ray ray welding are as follows Ray Power 1. A tube will be generated only when the ray power viscosity on the workpiece exceeds the threshold value( associated with the material), which marks the stable deep penetration. 2. still, the workpiece occurs If the ray power is lower than this threshold. only face melting. 3. Welding penetration is directly related to the ray power viscosity, is a function of the incident light ray power and ray focal spot. ii. Beam Focal Spot 1. The ray spot size is one of the most important variables in the ray welding, because it determines the power viscosity. 2. The ray focus diffraction limited spot size can be calculated according to the proposition of light diffraction, but due to the presence of the focus lens aberration, the factual spot than the advised value is too large. iii. Welding Speed 1. Welding speed has a lesser impact on penetration, increase the speed to make penetration shallow, but the too low speed will lead to inordinate melting of the material. 2. So, for a certain ray power and a certain consistence of a particular material have a suitable welding speed range. iv. Shielding Gas 1. The ray welding process is frequently used an inert gas to cover the molten pool. 2. Helium has delicate ionization, allows the ray has ray energy direct access to the workpiece face. 3. This is the most effective protection of the gas, but the price is more precious. 4. Argon gas is cheaper, thick, so the protection is better. 5. Nitrogen as a defensive gas is the cheapest, but doesn’t apply to certain types of pristine sword metallurgical aspects. Lens Focal Length 1. Focus mode, 63 254 mm is generally used in the focal length of the lens. 2. Focal spot size is commensurable to the focal length, the shorter the focal length the lower will be the spot. 3. The short focal length can ameliorate the power viscosity. vi. Focus Position 1. In order to maintain a sufficient power viscosity, the focal position is essential. 2. Changes in relative positions of the focus and the workpiece face directly affect the weld range and depth. 3. In utmost ray welding operations, the position of the focus is generally set below the face of the workpiece about the asked penetration depth of1/4. vii. Laser Beam Position 1. The ray ray position control the final quality of the weld, especially in the case of butt joints. 2. For illustration, when a hardened sword gear is welded to the barrel of the low- carbon sword, proper control of the ray ray position will be conducive to induce substantially low- carbon element composition of the weld, this weld having a good crack resistance.
