History of Metal Casting

Origins of Metal Casting

• 3200 BC: The oldest known casting, a copper frog, was cast in Mesopotamia.
• 2000 BC: Iron was discovered.
• 800-700 BC: Cast iron was first produced in China.
• 645 BC: The earliest known sand molding was done in China.
• 233 BC: Cast iron plowshares were poured in China.
• 500 AD: Cast crucible steel was first produced in India, but the process was lost.
• 1750: Benjamin Huntsman reinvented the process in England.

Middle Ages to 1800

• 1455: Dillenburg Castle in Germany was the first to use cast iron pipe for water transport.
• 1480: Vannoccio Biringuccio (1480–1539), considered the "father of the foundry industry," was born
• Biringuccio was the first to document the foundry process in writing in Italy.
• 1642: Saugus Iron Works, America's first iron foundry (and second industrial plant), was established near Lynn, Massachusetts.
• The first American iron casting, a Saugus pot, was poured there.
• 1709: Abraham Darby, an Englishman, created the first true foundry flask for sand and loam molding.
• 1720: Rene Antoine de Reaumur developed the first malleable iron, known as "European Whiteheart."
• 1730: Abraham Darby was the first to use coke as fuel in his melting furnace in Coalbrookdale, England.
• 1750: Benjamin Huntsman reinvented cast crucible steel process in England.
• The steel is completely melted, producing a uniform composition within the melt.
• Since the metal is completely molten, additional alloy elements can be added in the crucible during melting for alloy steel production.
• Prior steel production combined forging and tempering, and the metal never reached a molten state.
• 1776: Foundrymen signed the American Declaration of Independence including Charles Carroll, James Smith, George Taylor, James Wilson, George Ross, Philip Livingston, and Stephen Hopkins.
• 1794: John Wilkinson of England invented the cupola, first used in iron founding.
• The original had metal-cladding and used a steam engine to provide the air blast.

The 19th Century

• 1809: Centrifugal casting was developed by A.G. Eckhardt of Soho, England.
• 1815: The cupola was introduced in the United States in Baltimore, MD.
• 1818: The first cast steel was produced by the crucible process in the U.S. at the Valley Forge Foundry.
• 1825: Aluminum was isolated.
• 1826: Seth Boyden of Newark, NJ, developed a process to produce "blackheart" malleable iron.
• 1831: William Garrard established the first commercial crucible steel operation in the U.S. in Cincinnati, OH.
• 1837: The first dependable molding machine was marketed and used by the S. Jarvis Adams company in Pittsburgh.
• 1845: The open hearth furnace was developed.
• 1851: Sir Henry Bessemer and William Kelly invented a simple converter using air blasts to burn out impurities (silicon, manganese, and carbon) in pig iron.
• Bessemer obtained U.S. patents, even though Kelly was the first to use a converter.
• Kelly proved patent priority in 1857.
• 1863: Metallography, including etching, polishing, and microscopic evaluation of metal surfaces, was developed by Henry C. Sarby of Sheffield, England.
• Metallography was the first process to physically examine casting surfaces for quality analysis.
• 1867: James Nasmyth developed a gear-tilted foundry ladle, increasing worker safety and operational economy.
• 1870: Sandblasting was first used to clean large castings by R.E. Tilghman of Philadelphia.
• 1880–1887: The Sly tumbling mill was developed as the first cleaning machine for small castings.
• It reduced the time needed for hand-cleaning operations and produced a finer finished product.
• 1896: The American Foundrymen's Association (renamed American Foundrymen's Society in 1948 and now called the American Foundry Society) was formed.
• 1897: Investment casting was rediscovered by B.F. Philbrook of Iowa, who used it to cast dental inlays.

Early 20th Century

• 1906: The first electric arc furnace was used in the U.S. at Holcomb Steel Co. in Syracuse, NY.
• 1913: Harry Brearley in Sheffield, England, melted the first true stainless steel.
• 1913: Crucible Steel Casting Co.'s Lansdown, PA plant installed the first low-frequency electric furnace for special melting.
• 1923: The International Committee of Foundry Technical Associations was formed in Zurich, Switzerland.
• 1924: Dr. W.H. Hatfield invented 18/8 stainless steel (18% chromium, 8% nickel).
• 1930s: University of Michigan professors pioneered Spectrography for metal analysis.
• 1930: The first high-frequency coreless electric induction furnace in the U.S. was installed in the Lebanon Steel Foundry in Lebanon, PA.
• 1940: Wood flour was introduced into foundry practice as a sand additive.
• 1947: The Shell Process, invented by J. Croning of Germany during WWII, was discovered by U.S. officials and made public.
• 1948: Ductile iron, a cast iron with a fully spheroidal graphite structure, was developed.
• 1949: The U.S. patent for developing ductile iron was granted to K.D. Millis, A.P. Gagnebin, and N.B. Pilling of International Nickel Company.
• 1953: The Hotbox system of making and curing cores in one operation was developed, eliminating the need for dielectric drying ovens.
• 1958: H.F. Shroyer was granted a patent for the full mold process, the forerunner of the expendable pattern (lost foam) casting process.
• 1960s: Compactibility and methylene blue clay tests were developed for green sand control, along with high-pressure molding processes and fast-setting no-bake binders for sand.
• 1964: The first Disamatic molding machine was introduced.
• 1965: The Scanning Electron Microscope was invented by the Cambridge University Engineering Department in England.
• 1965: Cast metal matrix composites were first poured by Pradeep Rohatgi at International Nickel Company in Sterling Forest, NY.
• 1968: The Cold Box Process was introduced by L. Toriello and J. Robins for high-production core making.

Late 20th Century

• Early 1970s: The Semi-Solid Metalworking (SSM) process, combining aspects of casting and forging, was conceived at Massachusetts Institute of Technology.
• 1971: The Japanese developed V-Process molding using unbonded sand and a vacuum.
• 1971: Rheocasting was developed at Massachusetts Institute of Technology.
• 1971: The U.S. Congress passed the Clean Air Act and OSHA, the Occupational Health and Safety Act.
• 1972: The first production Austempered Ductile Iron (ADI) component was produced by Wagner Castings Company.
• 1974: Fiat introduced the in-mold process for ductile iron treatment.
• 1976: Compacted graphite iron (CGI), an iron with elongated graphite particles having rounded edges and roughened surfaces, was developed in the U.K.
• CGI has properties of both gray and ductile iron.
• 1982: The Warm Box binder system was introduced.
• 1993: The first foundry application of a plasma ladle refiner (melting and refining in one vessel) occurred at Maynard Steel Casting Company in Milwaukee, WI.
• 1995: Babcock and Wilcox, Barberton, OH, patented a lost foam vacuum casting process for producing stainless steel castings with low carbon content.
• 1996: Cast metal matrix composites were first used in a production model automobile, the brake rotors for the Lotus Elise.
• 1997: Electromagnetic casting processes were developed by Argonne and Inland Steel Corporation, reducing cost and energy expenditures in steel production.

Glossary of Metal Casting Terms

• Blackheart: An American type of malleable iron with a medium gray outer rim and a black interior.
• Coke: Coal derivative from distilling bituminous coal with no air, used as a fuel source.
• Cold Box Process: A core making process without heat. A phenolic resin is added to the sand and exposed to an accelerator to harden.
• Crucible: A ceramic pot for melting metal for casting.
• Cupola: A vertically oriented melting furnace where metal is melted in direct contact with fuel.
• Ductile Iron: Iron with spherical graphite achieved by adding magnesium, providing tensile strengths and flexibility than other irons.
• Green Sand: Natural sands combined with water and organic additives for creating molds.
• Investment Casting: A casting method using an expendable pattern of wax, plastic, or other material surrounded by a molding medium which is subjected to heat, leaving a cavity.
• Known as lost-wax molding.
• Malleable Iron: Iron altered in shape by hammering or pressure without fracture, with graphite nodules instead of flakes.
• Rheocasting: (flow casting) A metal forming process using semi-solid metal heated to a partly liquid state and pressed into the final form, resulting in closer tolerances, better surface finish, higher strength, and lighter weight.
• Shell Process: Coating clay-free silica sand with resin on a heated metal pattern, then heating the pattern and hardened shell to polymerize the resin sand mix is removed after hardening.
• Shell cores are made this was using the hot box process.
• Warm Box Process: A core making method where a warm corebox initiates curing, but cores finish curing outside the corebox and make solid cores by cycle.

Classification of Foundries

• A foundry is a commercial establishment for producing castings in molten metal, categorized by production pattern and metals to be cast.
• Types of Foundries include:
  • Captive
  • Jobbing
  • Production
  • Semi-Production

Foundry Types - Production Pattern

• Captive Foundry:
  • Part of a manufacturing organization that consumes the castings in its products.
• Jobbing Foundry:
  • Produces a small number of castings for different customers.
  • May have mass production facilities.
• Production Foundry:
  • Highly mechanized for mass production of castings.
• Semi-Production Foundry:
  • A combination of jobbing foundry and production foundry.

Foundry Types - Metal Casting

• Foundries classified by metal type:
  • Ferrous foundries (iron and steel)
  • Non-ferrous foundries (other metals)
• Ferrous Foundries further classified as:
  • Steel Foundry
  • Grey Cast Iron Foundry
  • Malleable Iron Foundry
  • Ductile Iron Foundry
• Non-ferrous Foundries further classified as:
  • Light Metals Foundry (aluminum and magnesium)
  • Copper, Brass, and Bronze Foundry
  • Lead, Tin, and Zinc Base Foundry

Material Properties of Foundry Metals

• Steel Foundry:
  • Produces plain carbon steel, low and high alloy steels.
• Grey Cast Iron Foundry:
  • Produces castings of grey color.
• Malleable Iron Foundry:
  • Produces castings that can be hammered or pressed into shape.
• Ductile Iron Foundry:
  • Produces castings that can be drawn into fine standards and easily molded.
• Light Metals Foundry:
  • Produces light metals using aluminum and magnesium alloys.
• Brass, Bronze, and Copper Foundry:
  • Uses alloys of germanium silver, aluminum phosphor, bronze, and manganese bronze brass.
• Lead, Tin, and Zinc Base Foundry:
  • Uses alloys of tin, antimony, copper, zinc, solder, britannia metal, and bronze.

Alloys

• Alloy materials play a crucial role in daily life in utensils, vehicles, computers, mobile phones, chairs, engineering, medical equipment, machinery, and tools.
• Alloys are made by combining two or more metal elements while in a molten state or by bonding metal powders.

Properties of Alloys

• Alloys have different desired properties:
  • Strength, visual attractiveness, malleability, hardness, low melting points, magnetic or electrical characteristics, high corrosion resistance.
• The internal and external characteristics change during the alloy-making process.
• Corrosion-resistant alloys can be formed and joined using conventional techniques.
• Solid solution alloy products are generally used in the annealed condition.
• Age-hardenable alloys are best fabricated in the annealed condition and directly aged or annealed and then aged for high strength.
• Corrosion-resistant alloys are typically formed at room temperature.
• Severe deformation may require multiple deformations with annealing between operations or heating to elevated temperatures for greater deformation.
• After hot or cold forming, parts should be annealed to restore corrosion resistance.
• Age-hardened alloys are not typically used in environments that induce stress corrosion tracking.

Types of Solid Solutions

• Substitutional Solid Solution Strengthening: Solute atoms replaces solvent atoms in lattice positions with some alloying elements are only soluble in small amounts, while others can form a solution over the entire range of binary compositions.
• Interstitial Solid Solution: Solute atom is small enough to fit into interstitial sites compressing the bonds of solvent atoms, causing deformation.

Solid Solution Properties

• Two crystalline solids mix to form a new crystalline solid or lattice.
• Mixing occurs by melting the solids into liquids at high temperatures and then cooling, or by depositing vapors onto substrates to form thin films.
• Mutual solubility depends on chemical properties and crystalline structure.
• Mixed lattice can be substitutional or interstitial.
• The properties of the solid solution can vary continuously over the range of concentrations.
• Solid solution strengthening improves the strength of pure metals by adding atoms of another element (alloying element), disrupting the lattice, impeding dislocation motion.
• Alloying beyond the solubility limit can form a second phase, leading to further strengthening.

Alloying Structure

• Substitutional Alloys: A second element replaces a metal atom; form when the metals are similar in size.
• Interstitial Alloys: A second element is much smaller than the solvent element.
• Heterogeneous Alloys: Components are not dispersed uniformly.

Common Types of Alloys

• Aluminum Alloys are conductive, heat-resistant, and tarnish-resistant and used in mechanical components like car engines, airplane body panels, and boat hulls.
• Bearing Alloys are used for accommodating pressure under sliding contact with another metal body.
• Corrosion-Resisting Alloys are made using noble metals resisting corrosion by separating forming a layer.
• Stainless steel and aluminum alloys are examples.
• Gold Alloys are used in jewelry and electronics.
• High-Strength Corrosion-Resistant Alloys are precipitation-hardenable versions of corrosion-resistant alloys offering more than twice the strength.
• Dental Alloy and Die-Casting Alloy are other alloys that are Widely used in daily life.
• Nickel Alloys react with specific chemicals to produce electricity and used in batteries and electric cars.
• Stainless Steel Products are made from iron, carbon, chromium and nickel are added to make stainless steel.

Steel Alloys

• Combining iron and carbon creates various steel products.
• Additional elements like molybdenum, nickel, silicon, boron, and manganese can be added to create different qualities.
• Super-Austenitic Stainless Steel Alloy (SASS Alloy): Enhanced with higher nickel and nitrogen for improved strength and corrosion resistance, containing about 6% molybdenum and sufficient chromium for resistance to both reducing and oxidizing environments.
• Properties of Alloys: Alloys are generally, Stronger and harder than the pure metal, Less malleable and ductile, More corrosion-resistant.
• Example: Bronze (made of copper and tin) is harder than copper and was historically used in the "Bronze Age."
• Alloys are designed with specific properties in mind, such as improved strength, durability, or corrosion resistance, depending on their composition and intended application.