Refractory metals are a class of metals that are extraordinarily resistant to heat and wear

Refractory metals are a class of metals that are extraordinarily resistant to heat and wear. The expression is mostly used in the context of materials science, metallurgy and engineering. The definition of which elements belong to this group differs. The most common definition includes five elements: two of the fifth period (niobium and molybdenum) and three of the sixth period (tantalum, tungsten, and rhenium). They all share some properties, including a melting point above 2000 °C and high hardness at room temperature. They are chemically inert and have a relatively high density. Their high melting points make powder metallurgy the method of choice for fabricating components from these metals. Some of their applications include tools to work metals at high temperatures, wire filaments, casting molds, and chemical reaction vessels in corrosive environments. Partly due to the high melting point, refractory metals are stable against creep deformation to very high temperatures.

H		He
Li	Be		B	C	N	O	F	Ne
Na	Mg		Al	Si	P	S	Cl	Ar
K	Ca	Sc		Ti	V	Cr	Mn	Fe	Co	Ni	Cu	Zn	Ga	Ge	As	Se	Br	Kr
Rb	Sr	Y		Zr	Nb	Mo	Tc	Ru	Rh	Pd	Ag	Cd	In	Sn	Sb	Te	I	Xe
Cs	Ba	La	*	Hf	Ta	W	Re	Os	Ir	Pt	Au	Hg	Tl	Pb	Bi	Po	At	Rn
Fr	Ra	Ac	**	Rf	Db	Sg	Bh	Hs	Mt	Ds	Rg	Cn	Uut	Uuq	Uup	Uuh	Uus	Uuo
	*	Ce	Pr	Nd	Pm	Sm	Eu	Gd	Tb	Dy	Ho	Er	Tm	Yb	Lu
	**	Th	Pa	U	Np	Pu	Am	Cm	Bk	Cf	Es	Fm	Md	No	Lr

Refractory metals

Wider definition of refractory metals

Definition

Most definitions of the term \'refractory metals\' list the extraordinarly high melting point as a key requirement for inclusion. By one definition, a melting point above 4,000 °F (2,200 °C) is necessary to qualify. The five elements niobium, molybdenum, tantalum, tungsten and rhenium are included in all definitions, while the wider definition, including all elements with a melting point above 2,123 K(1,850 °C), includes a varying number of nine additional elements, titanium, vanadium, chromium, zirconium, hafnium, ruthenium, osmium and iridium. Transuranium elements (those above uranium, which are all unstable and not found naturally on earth) and technetium are never considered to be part of the refractory metals.

Refractory Materials, Ceramic Fiber Blanket, Plastics, Castables

supplies a unique range of Metallurgical Frits to metal producers throughout the world. These frits are used as lubrication agents in processes, such as, the forging process and other techniques. They are a good alternative for graphite lubricants. As a processing aid, Pemco’s Metallurgical Frits significantly enhance the efficiency of the process and extend the lifespan of the equipment used. (Refractory materials such as linings and bricks) In 2011, Pemco’s business will have been ‘up and running’ for a century. The phrase ‘up and running’ is carefully chosen because I think it captures the essence of what we were a hundred years ago, as well as what we still are today. That is to say we are a pioneering business that is still very much on the move and moving forward. If you work for Pemco International, or with Pemco as a customer, you will sense that pioneering spirit in the ‘way we work’. Pemco people have a deep-seated passion about not only our products, but our customers’ technical issues and the how end-users demands are evolving. When customers buy from Pemco, they are not generally buying only a quality product, but a solutions-provider whose people have the know-how, energy and commitment to deliver. Pemco people and our solutions-based approach are enduring differentiators for us in the marketplace, but not the only ones. Porcelain and Glass Enamels, Conductive Coatings, Specialty Frits and related products are our sole focus – in fact it’s our core business. We have been around a long time and can be relied upon to be there in the future, with long-standing relationships with customers being a hallmark of Pemco. With an intent to harness our R&D technical capabilities and unrivalled global reach, our eyes are very much on exciting opportunities to grow our market share and, as is the characteristic of any pioneer, open up new categories. Only a lean and competitive company will be able to seize these opportunities and Pemco’s leadership team, with a blend of experience drawn from inside and outside our industry, has the drive and vision to ensure we always ‘compete to win’.