4A. Basic Metalworking.pdf

BASIC METALWORKING Definition Metalworking is the process of forming and shaping metals To create useful tools, objects, equipment parts, and structures Processes involved forming cutting, joining Techniques used cutting weld...

BASIC METALWORKING Definition Metalworking is the process of forming and shaping metals To create useful tools, objects, equipment parts, and structures Processes involved forming cutting, joining Techniques used cutting welding casting molding Materials used for metalworking: ferrous and non-ferrous metals steel aluminium gold silver bronze iron, and more History Been done for thousands of years from Pharaohs in Egypt to Mayans in North America oldest known evidence - a copper pendant uncovered in Iraq and dates back to 8,700 BC. a way for civilizations to communicate status, religious beliefs, etc. a practical way to build tools and structures practiced by artisans, blacksmiths, alchemists, contractors, etc. ancient techniques are still used today- soldering and welding metallic ores have been extracted from the earth for thousands of years, Compiled for ME 2102 – Workshop Theory and Practice by JGMilitar, PME (Reference: https://www.thecrucible.org/guides/metalworking/)  in modern times, metals have become even more critical to humanity advancements in technology and transportation require metalworking-it is all around us, from the fabrication of electronics to automobiles. Metalworking Techniques Cutting  removing material from metal using sawing, milling, turning, etc.  use tools/equipment like hacksaw, milling machine, lathe machine, shaper, plasma cutter, CNC machines, etc.  used in metalworking fabrication shops, automotive repair, and construction Joining  combining several pieces of metal with heat by welding or soldering  welding uses welding machines to join ferrous/non-ferrous metals— works well for larger projects  soldering is used to fuse different types of precious metals together by melting solder—works well with smaller projects Forming  the process of re-shaping and fabricating metal objects without adding (joining) or removing (cutting) any material  done through a combination of heat and pressure  forging and bending are essential methods of forming  e.g. to make a bend or curve in a metal, the metal is heated (forged) then hammered over an anvil Casting  the process of pouring molten metal into cavities shaped in stone, plaster, sand, etc.  common methods are lost wax casting, die casting, and sand casting Compiled for ME 2102 – Workshop Theory and Practice by JGMilitar, PME (Reference: https://www.thecrucible.org/guides/metalworking/) Cutting Processes & Techniques  metals are cut and separated throughout the metalworking process to build structures, make tools, etc.  there are numerous metal cutting methods—from simple handheld tools to a variety of more advanced machines & equipment Milling  process of removing precise amounts of material from a greater piece  the machine rotates a cutting tool and brings the cutting tool into contact with a workpiece  the mill or milling machine and the lathe are the cornerstone of any machine shop o produce pieces with great precision, repeatability & accuracy Turning  machining process where the cutting tool moves linearly while the workpiece rotates, strategically removing material from a workpiece  lathe machines are traditionally used in turning as the leading principal machine tool  Advanced machines include CNC (Computer Numerical Controlled) machines for more automated process Grinding  use abrasive process to remove material from a workpiece  typically as finishing stages in metalworking  range from handheld angle grinders to bench grinders to more advanced CNC machines  creates very fine finishes & cuts using abrasive wheel made from stone, diamonds, or inorganic material Drilling  creates holes in metal using handheld drill, dill press, lathe machine, milling machine or CNC machine Compiled for ME 2102 – Workshop Theory and Practice by JGMilitar, PME (Reference: https://www.thecrucible.org/guides/metalworking/)   make sure to lubricate the drill bits with cutting fluids to Joining processes & techniques  uses heat and pressure to create a larger piece or build a structure  welding & riveting are excellent techniques for larger projects that bear weight  soldering is typically used for smaller materials like jewelry and sculptural objects Welding  fabrication process that joins materials through pressure and heat  uses different types of welding, each with specific practical applications (MIG, TIG, SMAW, Flux, Energy Beam, Atomic Hydrogen, Oxy-acetylene, Plasma Arc) Soldering  joins metals by melting a filler material on top of the metals being joined to make a reliable electrical bridge  usually, a low-temperature alloy is melted into the joint, fusing the metals into one solid piece  uses electric soldering iron or gas-powered torch  commonly used in plumbing, electronics, and other smaller metal joining works Riveting  uses rivets—permanent mechanical fasteners that can create kinetic joints in a workpiece or reinforce the structural integrity of a larger object—to join metal workpiece  rivets are smooth metallic cylinders with a head on one end (like hollow nails).  ideal for joining pieces that are lightweight and require high strength Forming processes & techniques Compiled for ME 2102 – Workshop Theory and Practice by JGMilitar, PME (Reference: https://www.thecrucible.org/guides/metalworking/)   reshaping /manipulating the shape of metal—can be done hot or cold  choice of forming process depends on the o type of metal o equipment available, and o desired outcome Forging  metal is heated in the forge (furnace) then hammered and bent into the desired shape  the blacksmith (metalworker) may use a handheld hammer for smaller objects or industrial power hammer for larger projects  forged metals are incredibly strong and are typically made of iron and steel Roll Forming  involves the continuous bending of a long strip of sheet metal through a forming mill (or rollers) at room temperature  inherently flexible, precise and can form metals up to 0.25 in. thick Rolling  process in which metal stock is passed through a rolling mill to reduce thickness or make the thickness uniform  can be done hot or cold – hot rolling is used to produce sheet metal and larger workpieces  cold rolling is used for smaller objects—increases the metal’s strength and improves the surface finish Casting Processes & Techniques  solid metal objects are formed by pouring molten metal into a mold where it is cooled and extracted from  cost and time effective process compared to other forming processes Compiled for ME 2102 – Workshop Theory and Practice by JGMilitar, PME (Reference: https://www.thecrucible.org/guides/metalworking/)   common methods include o investment or lost wax o die casting o sand casting Investment or Lost Wax Casting the process involves the following steps  carving/shaping the desired shape in wax  creating a plaster mold around it  burning out the wax in an oven  melted metal is poured into the mold Die Casting  an automated and fast process that forces molten metal into a mold under high pressure  the mold is made from two machined steel dies and metal is injected into the mold at a high speed  usually uses alloys with low melting point like zinc, copper, aluminium and magnesium Sand Casting  sand casting uses sand mixed with a bonding agent as a mold material such as clay  molten metal is poured/flowed into the mold to create a solid object  commonly used in foundries and is relatively inexpensive Compiled for ME 2102 – Workshop Theory and Practice by JGMilitar, PME (Reference: https://www.thecrucible.org/guides/metalworking/)