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Questions and Answers
Tubal-Cain was known as a master of bronze, iron, and all other types of metals during the mid-10th century BCE.
Tubal-Cain was known as a master of bronze, iron, and all other types of metals during the mid-10th century BCE.
True
The Iron Pillar of Delhi is considered to be the largest weldment constructed during the Middle Ages.
The Iron Pillar of Delhi is considered to be the largest weldment constructed during the Middle Ages.
True
Edmund Davy discovered that electric arcs could be created using two carbon rods connected to a weak battery.
Edmund Davy discovered that electric arcs could be created using two carbon rods connected to a weak battery.
False
Acetylene was successfully stored in glass bottles without any safety issues.
Acetylene was successfully stored in glass bottles without any safety issues.
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Modern gas welding techniques primarily utilize a combination of oxygen and coal gas for safety.
Modern gas welding techniques primarily utilize a combination of oxygen and coal gas for safety.
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In the 1960s, a man from Weston, W.Va., created a torch powered by gasoline and oxygen.
In the 1960s, a man from Weston, W.Va., created a torch powered by gasoline and oxygen.
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Acetylene is considered to be safer than a certain welding method that never really caught on due to temperature variations.
Acetylene is considered to be safer than a certain welding method that never really caught on due to temperature variations.
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World War I significantly increased the demand for riveting techniques in shipbuilding.
World War I significantly increased the demand for riveting techniques in shipbuilding.
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The American Welding Society was established in 1919 by a committee formed during World War I.
The American Welding Society was established in 1919 by a committee formed during World War I.
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Hammering was not used for decorative metalwork until the process of soldering was invented.
Hammering was not used for decorative metalwork until the process of soldering was invented.
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Metalwork encompasses a variety of metal types, including gold, copper, and plastic.
Metalwork encompasses a variety of metal types, including gold, copper, and plastic.
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Embossing involves raising designs from the front side of a metal plate.
Embossing involves raising designs from the front side of a metal plate.
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The earliest man-made objects were primarily made of metals such as bronze and silver.
The earliest man-made objects were primarily made of metals such as bronze and silver.
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The Egyptian museum in Cairo features a life-size statue of the pharaoh Pepi I as an example of decorated metalwork.
The Egyptian museum in Cairo features a life-size statue of the pharaoh Pepi I as an example of decorated metalwork.
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Hammering is not involved in the process of creating ornament in relief.
Hammering is not involved in the process of creating ornament in relief.
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The specialized tool known as a snarling iron is used for chasing only.
The specialized tool known as a snarling iron is used for chasing only.
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Engraving involves cutting or incising a line into the surface of the material.
Engraving involves cutting or incising a line into the surface of the material.
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The technique of damascening is related to the use of gold wire on the surfaces of various metals.
The technique of damascening is related to the use of gold wire on the surfaces of various metals.
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Chasing is only used for intaglio effects and cannot produce relief effects.
Chasing is only used for intaglio effects and cannot produce relief effects.
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Niello is a process involving the inlaying of designs with a silver sulfide mixture.
Niello is a process involving the inlaying of designs with a silver sulfide mixture.
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Embossed work is created by only bossing the design up from the back without any chasing.
Embossed work is created by only bossing the design up from the back without any chasing.
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Mechanical means can be used to produce ornament in relief by pressing metal into molds.
Mechanical means can be used to produce ornament in relief by pressing metal into molds.
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The first authors to write about niello preparation were from the 20th century.
The first authors to write about niello preparation were from the 20th century.
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Carving is the term used when pressure is applied with a hammer during engraving.
Carving is the term used when pressure is applied with a hammer during engraving.
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Chrome Vanadium Steel is primarily used for making cutting tools.
Chrome Vanadium Steel is primarily used for making cutting tools.
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Manganese steels can be adjusted to create different properties by varying the amounts used.
Manganese steels can be adjusted to create different properties by varying the amounts used.
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Bronze is defined as an alloy containing 84% tin and 16% copper.
Bronze is defined as an alloy containing 84% tin and 16% copper.
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Duralumin is recognized in the metalworking industries as a heat-treated aluminum alloy classified as 2017-T.
Duralumin is recognized in the metalworking industries as a heat-treated aluminum alloy classified as 2017-T.
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Lead is a nonferrous metal and is primarily known for its corrosion resistance.
Lead is a nonferrous metal and is primarily known for its corrosion resistance.
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Copper-nickel alloys are used exclusively for constructing small storage tanks.
Copper-nickel alloys are used exclusively for constructing small storage tanks.
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Study Notes
Metalworking Throughout History
- Tubal-Cain, a figure from the mid-10th century BCE, is credited with being a master of bronze, iron, and other metals.
- The Iron Age, while significant, is not the beginning of metalworking.
- The Iron Pillar of Delhi (constructed during the Middle Ages) is notable for being the largest welded structure of the time.
- Forging was a common metalworking technique, even in the 20th century.
The Davys' Discoveries
- Edmund Davy discovered acetylene in the early 1800s.
- Sir Humphry Davy discovered the electric arc, which became a welding process used for galvanized sheet metal.
- Gas welding, brazing, and cutting with oxygen and coal gas or hydrogen gained popularity in the late 1800s.
- Storing acetylene was initially problematic due to its low flash point and expansiveness.
- Acetylene is currently stored in cylinders filled with a porous material, like acoustic ceiling material, and stabilized with acetone.
World War I
- World War I significantly boosted the need for welding due to its cost-effectiveness and efficiency compared to riveting.
- The American Welding Society was established in 1919 by the Wartime Welding Committee, with a mission to advance welding and related processes.
Metalwork
- Metalwork encompasses objects of various metals like copper, iron, silver, bronze, lead, gold, and brass.
- The earliest human-made objects were made from materials like stone, wood, bone, and earth.
- Metalwork includes a wide array of articles, such as vessels, utensils, ceremonial objects, decorative items, architectural elements, personal ornaments, sculptures, and weapons.
General Processes and Techniques
- Many metalworking techniques used today were developed in ancient times.
Hammering and Casting
- Hammering was initially the primary method for decorative metalwork.
- Separate parts were hammered out and joined together through rivets or pinned onto a solid core.
- Hammered copper plates were shaped into statues, with pieces joined using rivets.
- An example of this technique is the life-size statue of Pharaoh Pepi I in the Egyptian Museum in Cairo.
Embossing, or Repoussé
- Embossing (repoussé) involves raising ornamentation on metal from the reverse side.
- The design is first drawn on the metal surface and outlined with a tracer, transferred to the back of the plate.
- The plate is embedded face down in an asphalt block, and the raised portions are hammered inwards.
- The process is continued with the plate flipped, hammering the background into the asphalt.
- This repeated process of hammering and re-embedding, followed by chasing, creates the final design.
- Specific tools are used for tracing, bossing, chasing, and accessing less accessible areas.
- Repoussé is also achieved mechanically, pressing thin metal into molds, between dies, or over stamps.
Chasing
- Chasing involves using hammers and punches on the metal surface to create intaglio (incised lines) or relief.
- The design is traced on the surface, and relief is often achieved by hammering down surrounding areas.
- Chasing can simulate embossed work, but the design is raised from the back in embossing.
- Chasing is used for finishing detailed embossed work and for touching up cast work.
Engraving
- Engraving involves cutting or incising lines into metal using a cutting tool, typically by hand pressure.
- Carving resembles engraving but uses a hammer to apply pressure.
Inlaying
- Damascening, an ornamental technique originating in the East, involves inlaying gold wire (sometimes silver or copper) onto iron, steel, or bronze.
- The surface for inlay is finely undercut, and the gold thread is hammered into the cuts, securing it.
- Niello involves inlaying ornamental designs with a silver sulfide mixture.
Chrome Vanadium Steel
- Used for high-strength components like crankshafts, gears, axles, and high-quality hand tools.
Tungsten Steel
- Expensive to produce, primarily used for cutting tools like drills, lathe tools, and milling cutters.
Molybdenum
- A substitute for tungsten, used in cheaper grades of high-speed steel and in carbon molybdenum high-pressure tubing.
Manganese Steels
- Used for various properties depending on the amount present:
- Small amounts: Strong, free-machining steels
- Larger amounts: Brittle steel
- Significant amounts: Tough, wear-resistant steel (after heat treatment)
Nonferrous Metals
- Contain either no iron or negligible amounts, making them nonmagnetic.
- Commonly used in various applications.
Copper
- A popular commercial metal, used in various alloys.
- Used for protective coatings on sheets and rods, and in making ball floats, containers, and soldering coppers.
True Brass
- An alloy of copper and zinc, often with additional alloys for specific properties.
- Sheets and strips are available in various grades.
Bronze
- Originally an alloy of 84% copper and 16% tin, it was the best metal before steel-making techniques.
- The term "bronze" now refers to any copper-based alloy with a bronze-like appearance.
Copper-Nickel Alloys
- Nickel improves wear and corrosion resistance.
- Some alloys are used for saltwater piping systems.
- Sheet forms are used for small storage tanks and hot-water reservoirs.
Lead
- A heavy, soft, and malleable metal.
- Has a grayish surface, with a white color when scraped or scratched.
Zinc
- Used as a protective coating called galvanizing on iron or steel.
Tin
- A significant alloy that adds corrosion resistance.
Aluminum
- Easy to work with, aesthetically pleasing, and lightweight.
- Requires alloys for increased strength.
Duralumin
- Originally one of the first strong structural aluminum alloys.
- Now classified as 2017-T in metalworking, with "T" indicating heat-treated.
Thermoplastics
- Some examples include cellulose nitrate (celluloid), polythene, polyvinyl acetate, and polyvinyl chloride (PVC).
Mechanical Properties of Common Engineering Materials
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Elasticity: The ability of a material to regain its original shape after deformation when external forces are removed.
- Mild steel and rubber are elastic, but steel is more elastic than rubber.
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Plasticity: The ability of a material to undergo permanent deformation when stress exceeds the yield point.
- Materials ideally deform without stress increase under plastic conditions.
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Hardness: The ability of a material to resist permanent deformation, penetration, and indentation.
- Measured by indentations from various indenters (Brinnel, Rockwell, Vickers).
- Related to yield pressure (MPa).
-
Ductility: The ability of a material to be drawn out or elongated significantly before rupture.
- Measured by percentage elongation or reduction in area before rupture.
- Ductile materials typically have an elongation exceeding 15%, while brittle materials are below 5%.
- Lead, copper, aluminum, and mild steel are ductile.
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Malleability: A specific case of ductility, where materials can be rolled into thin sheets.
- Not necessarily as strong as ductile materials.
- Lead, soft steel, wrought iron, copper, and aluminum are malleable in decreasing order.
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Brittleness: The opposite of ductility.
- Brittle materials show little deformation before fracture and fail suddenly.
- Typically have an elongation below 5%.
- Cast iron, glass, and ceramics are brittle.
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Resilience: The ability of a material to resist shock and impact by storing energy.
- Measured by strain energy absorbed per unit volume.
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Toughness: The ability of a material to withstand twisting, bending, or stretching under impact load or high stress before rupture.
- Essentially the material's capacity to absorb energy in the plastic zone.
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Description
Explore the fascinating developments in metallurgy and welding techniques throughout history. From Tubal-Cain's mastery of metals to modern gas welding, this quiz covers significant milestones and innovations. Test your knowledge of these key figures and inventions in metalworking.
