Alloy: is a mixture of metals or a mixture of a metal and another element. Alloys are defined by metallic bonding character.  An alloy may be a solid solution of metal elements (a single phase) or a mixture of metallic phases (two or more solutions). Intermetallic compounds are alloys with a defined stoichiometry and crystal structure. Zintl phases are also sometimes considered alloys depending on bond types (see also: Van Arkel-Ketelaar triangle for information on classifying bonding in binary compounds). Alloys are used in a wide variety of applications. In some cases, a combination of metals may reduce the overall cost of the material while preserving important properties. In other cases, the combination of metals imparts synergistic properties to the constituent metal elements such as corrosion resistance or mechanical strength. Examples of alloys are steel, solder, brass, pewter, duralumin, phosphor bronze and amalgams. The alloy constituents are usually measured by mass. Alloys are usually classified as substitutional or interstitial alloys, depending on the atomic arrangement that forms the alloy. They can be further classified as homogeneous (consisting of a single phase), or heterogeneous (consisting of two or more phases) or intermetallic.
Hastelloy: Hastelloy is the registered trademark name of Haynes International, Inc. The trademark is applied as the prefix name of a range of twenty-two different highly corrosion-resistant metal alloys, loosely grouped by the metallurgical industry under the material term “superalloys” or “high-performance alloys”. The predominant alloying ingredient is typically the transition metal nickel. Other alloying ingredients are added to nickel in each of the subcategories of this trademark designation and include varying percentages of the elements molybdenum, chromium, cobalt, iron, copper, manganese, titanium, zirconium, aluminum, carbon, and tungsten. The primary function of the Hastelloy super alloys is that of effective survival under high-temperature, high-stress service in a moderately to severely corrosive, and/or erosion-prone environment where more common and less expensive iron-based alloys would fail, including the pressure vessels of some nuclear reactors, chemical reactors, distillation equipment, and pipes and valves in chemical industry. Although a super alloy, Hastelloy does experience degradation due to fabricating and handling. Electropolishing or passivation of Hastelloy can improve corrosion resistance.
Inconel 625: is a nonmagnetic, corrosion and oxidation resistant, nickel-base alloy. It has high strength and toughness in the temperature range cryogenic to 2000®F (1093®C) which is derived largely from the solid solution effects of the refractory metals, columbium and molybdenum, in a nickel-chromium matrix. Alloy 625 has excellent fatigue strength and stress-corrosion cracking resistance to chloride ions. Typical applications for Alloy 625 have included heat shields, furnace hardware, gas turbine engine ducting, combustion liners and spray bars, chemical plant hardware and special seawater applications
INCONEL 718: (UNS N07718/W.Nr. 2.4668) is a high-strength, corrosion-resistant nickel chromium material used at -423° to 1300°F. Typical composition limits are shown in Table 1. The age-hardenable alloy can be readily fabricated, even into complex parts. Its welding characteristics, especially its resistance to postweld cracking, are outstanding. The ease and economy with which INCONEL alloy 718 can be fabricated, combined with good tensile, fatigue, creep, and rupture strength, have resulted in its use in a wide range of applications. Examples of these are components for liquid fueled rockets, rings, casings and various formed sheet metal parts for aircraft and land-based gas turbine engines, and cryogenic tankage. It is also used for fasteners and instrumentation parts.
INCONEL alloy X-750: (UNS N07750/W. Nr. 2.4669) is a precipitation-hardenable nickel-chromium alloy used for its corrosion and oxidation resistance and high strength at temperatures to 1300°F. Although much of the effect of precipitation hardening is lost with increasing temperature over 1300°F, heat-treated material has useful strength up to 1800°F. Alloy X-750 also has excellent properties down to cryogenic temperatures. The economics of INCONEL alloy X-750 coupled with its availability in all standard mill forms has resulted in applications in a wide variety of industrial fields. In gas turbines, it is used for rotor blades and wheels, bolts, and other structural members. INCONEL alloy X-750 is used extensively in rocket-engine thrust chambers. Airframe applications include thrust reversers and hot-air ducting systems. Large pressure vessels are formed from INCONEL alloy X-750. Other applications are heat-treating fixtures, forming tools, extrusion dies, and test machine grips. For springs and fasteners, INCONEL alloy X-750 is used from sub-zero to 1200°F
Invar: Invar, also known generically as FeNi36 (64FeNi in the US), is a nickel–iron alloy notable for its uniquely low coefficient of thermal expansion
Kovar: As one of the single largest users of KOVAR® in the country (KOVAR® is a registered trademark of CRS Holdings, Inc), Romac takes pride in specializing in machining and stamping this material that is used in numerous sealing and brazing applications. While most machine shops and stamping companies shy away from this material, we have been stamping and machining KOVAR® for over 40 years. Learn More
Monel: Monel is a group of nickel alloys, primarily composed of nickel (up to 67%) and copper, with small amounts of iron, manganese, carbon, and silicon
Nickel 200: is commercially pure (99.6%) wrought nickel. It has good mechanical properties and excellent resistance to many corrosive environments. Other useful features of the alloy are its magnetic and magnetostrictive properties, high thermal and electrical conductivities, low gas content and low vapor pressure. The corrosion resistance of Nickel 200 makes it particularly useful for maintaining product purity in the handling of foods, synthetic fibers, and caustic alkalies; and also in structural applications where resistance to corrosion is a prime consideration. Other applications include chemical shipping drums, electrical and electronic parts, aerospace and missile components
Nickel 201: is the low-carbon version of Nickel 200. Composition is shown in Table 28. Typical applications are caustic evaporators, combustion boats, plater bars, and electronic components. Nickel 201, because of its low base hardness and lower work-hardening rate, is particularly suited for spinning and cold forming. It is preferred to Nickel 200 for applications involving exposure to temperatures above 600°F (315°C).
Stainless Steel: In metallurgy, stainless steel, also known as inox steel or inox from French “inoxydable”, is a steel alloy with a minimum of 10.5% chromium content by mass.Stainless steel does not readily corrode, rust or stain with water as ordinary steel does.
Stainless Steel 13-8: is a precipitation-hardening martensitic Stainless Steel capable of high strength, excellent hardness, and superior toughness along with good levels of resistance to both general corrosion and stress-corrosion cracking. Composed of about 13% Chromium and 8% Nickel, Stainless 13-8 has good fabrication characteristics and can be age-hardened by a single low temperature treatment. Cold work prior to aging increases the aging, especially for lower aging temperatures. Additionally, 13-8 Stainless exhibits good ductility and toughness. Compared to other ferrous-base materials, this alloy offers a high level of useful mechanical properties under severe environmental conditions. Stainless Steel 13-8 is found in such applications as valve parts, fittings, cold-headed and machined fasteners, shafts, landing gear parts, pins, lock washers, aircraft components, nuclear reactor components and petrochemical applications requiring resistance to st
Stainless Steel PH 15-7 Mo® is a semi-austenitic precipitation-hardening stainless steel that provides high strength and hardness, good corrosion resistance and minimum distortion on heat treatment. It is easily formed in the annealed condition and develops an effective balance of properties by simple heat treatments. For applications requiring exceptionally high strength, cold-reduced PH 15-7 Mo Stainless Steel in Condition CH 900 is particularly useful for applications permitting limited ductility and workability. This alloy is particularly beneficial for a wide range of applications that include retaining rings, springs, diaphragms, aircraft bulkheads, welded and brazed honeycomb paneling and other aircraft components requiring high strength at elevated temperatures
Titanium: a dark-gray or silvery, lustrous, very hard, light, corrosion-resistant, metallic element, occurring combined in various minerals: used in metallurgy to remove oxygen and nitrogen from steel and to toughen it. Symbol: Ti; atomic weight: 47.90; atomic number: 22; specific gravity: 4.5 at 20°C. Origin of titanium