Alloy materials development

Chromium—Cobalt—Iron Alloys. In 1971, a family of ductile Cr—Co—Fe permanent-magnet alloys was developed (79). The Cr—Co—Fe alloys are analogous to the Alnicos in metallurgical stmcture and in permanent magnetic properties, but are cold formable at room temperature. Equivalent magnetic properties also can be attained with substantially less Co, thereby offering savings in materials cost. 

The austenitic iron—chromium—nickel alloys were developed in Germany around 1910 in a search for materials for use in pyrometer tubes. Further work led to the widely used versatile 18% chromium—8% nickel steels, the socaHed 18—8. 

Driven by these impending limits to blade cooling emphasis has switched back to materials development. Because of the saturation in the development of nickel alloys, more revolutionary approaches are being explored. 

Any major materials development programme, such as that on the eutectic superalloys, can only be undertaken if a successful outcome would be cost effective. As Fig. 20.10 shows, the costs of development can be colossal. Even before a new material is out of the laboratory, 5 to 10 million pounds (8 to 15 million dollars) can have been spent, and failure in an engine test can be expensive. Because the performance of a new alloy cannot finally be verified until it has been extensively flight-tested, at each stage of development risk decisions have to be taken whether to press ahead, or cut losses and abandon the programme. 

T. A. Ramanarayanan and C. M. Chun, Chapter 6 Metal Dusting Corrosion of Metals and Alloys, New Development in High Temperature Corrosion and Protection of Materials, Ed. W. Gao and Z. Li, Woodhead Publishing Ltd., Cambridge, UK p.80-116 (2008). 

Abstract This review highlights how molecular Zintl compounds can be used to create new materials with a variety of novel opto-electronic and gas absorption properties. The generality of the synthetic approach described in this chapter on coupling various group-IV Zintl clusters provides an important tool for the design of new kinds of periodically ordered mesoporous semiconductors with tunable chemical and physical properties. We illustrate the potential of Zintl compounds to produce highly porous non-oxidic semiconductors, and we also cover the recent advances in the development of mesoporous elemental-based, metal-chalcogenide, and binary intermetallic alloy materials. The principles behind this approach and some perspectives for application of the derived materials are discussed. 

Much recent work has been carried out on the development of special alloy materials capable of withstanding the hostile environment found in deep, hot high pressure sour gas wells. Asphahani has recently surveyed (14) progress to date in the field with particular reference to the CO2/H2S/CI environment. The inadequacy of typical 410 type stainless steels in this environment has led to a search for more resistant alloy materials and high iron, nickel base alloys such as Incoloy 825 (30 Fe,... 

Aluminum powder metallurgy continues to receive high research and development priority. A major objective is to produce final aluminum parts by direct pressing of rapidly solidified aluminum particles. The process handles high-strength aluminum alloy materials. 

The special needs of the space program motivated the search for composite materials for other reasons also. For example, during tests of the first Atlas ICBM (intercontinental ballistic missile), engineers were concerned that the rocket s metallic components would not survive the missile s reentry into the atmosphere they feared it would melt down because of the intense heat to which it was exposed. By the late 1950s, therefore, aerospace researchers had begun to look for satisfactory substitutes for metal alloys for such applications. With that research, the modern held of composite design was horn. One of the first composites tested consisted of pieces of glass embedded in melamine, purported to be the first composite material developed for aerospace applications. 

Probably the first successful and widespread clinical use of biomaterials occurred in the early 1900s, when a number of metals and alloys were developed to stabilize bones that had been fractured. These materials were used to form bone plates that held the broken ends of bones in place until they grew back together. After healing, the plates were removed, if possible, or, if not, left in the patient s body. 

Many of the new materials developed by early humans were modeled on substances found in nature. The first alloys, for example, were little more than artificial copies of substances produced when fire, lightning, or some other natural source of energy caused the fusion of naturally occurring materials on the Earth s surface. Over time, however, people learned how to modify these processes to produce new alloys and other materials that were superior to those found in nature. This pattern has dominated materials research since the dawn of time. Many of the best new materials available today were created when scientists discovered how nature makes its composites and found new and better ways to duplicate those processes. One of the most exciting fields of materials research today involves the development of new biomaterials, substances similar to naturally occurring products found in living organisms that can be used in a host of new ways by medical workers. 

Bullet lead can be either soft lead or lead hardened by antimony, by tin, or by both. Mercury was also used to harden lead in the early days of bullet development. The quantity of alloying materials varies considerably, for example, antimony <0.5% to as high as 12% but typically 2% to 5%, tin <0.5% to 10% but typically 3% to 5%. A larger amount of tin is required to give the same degree of hardness as that of antimony consequently, for cost reasons, antimony is more frequently used. 

Another magical titanium material is the alloy nitinol, which can remember a previous shape and return to it. Nitinol consists of 55% nickel and 45% titanium, a combination which corresponds to one atom of nickel for each atom of titanium. This alloy was developed in the US in the 1960s at the Nickel Titanium Naval Ordnance Laboratory which gave rise to the name Ni-Ti-NOL. This alloy is best known as spectacle frames which can be twisted in a way that would be permanently deformed were they to be made of any other metal but, because they are made of nitinol, they will jump back to their original shape when the pressure is removed. 

HK 40 alloy, and HP 25/35 modified alloys were used as tube materials. However these materials developed various operating problems as rates increased and longer service lives were needed for economical operation.88... 

Rejueven8Plus is made from 95% NatureWorks PLA and was specifically developed for printed applications. This alloy material has enhanced characteristics over standard PLA that makes it similar to PET. Secondary processing criteria further raise its heat resistance properties to well over 150 °F, which is much higher than the standard PLA maximum temperature range of about 105-120 °F. 

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