A low thermal expansion alloy having a high rigidity and a low thermal expansion coefficient comprising, by mass %, C: 0.040% or less, Si: 0.25% or less, Mn: 0.15 to 0.50%, Cr: 8.50 to 10.0%, Ni: 0 to 5.00%, and Co: 43.0 to 56.0%, S: 0 to 0.050%, and Se: 0 to 0.050% and having a balance of Fe and unavoidable impurities, the contents of Ni, Co, and Mn represented by [Ni], [Co], and [Mn] satisfying 55.7≤2.2[Ni]+[Co]+1.7[Mn]≤56.7 and the structure being an austenite single phase.

The disclosure provides high strength high-entropy alloys with compositions (in atomic %) of Fe.sub.aNi.sub.bMn.sub.cAl.sub.dCr.sub.eC.sub.f where 37-43 atomic %, b is 8-14 atomic %, c is 27-33 atomic %, d is 4-10 atomic %, e is 10-14 atomic %, and f is 0-2 atomic %.

The disclosure provides high strength high-entropy alloys with compositions (in atomic %) of Fe.sub.aNi.sub.bMn.sub.cAl.sub.dCr.sub.eC.sub.f where 37-43 atomic %, b is 8-14 atomic %, c is 27-33 atomic %, d is 4-10 atomic %, e is 10-14 atomic %, and f is 0-2 atomic %.

The disclosure provides for a layered metal with resistance to hydrogen induced cracking and method of production thereof, comprising a core metal alloy and a skin metal alloy. The core metal alloy comprises twinned boundaries. The core metal alloy has undergone plastic deformation and a heat treatment. The core metal alloy comprises nickel and cobalt. The skin metal alloy is disposed on the core metal alloy, wherein the skin metal alloy comprises an entropy greater than the core metal alloy. The core metal alloy comprises a greater density of twinned boundaries than the skin metal alloy. The skin metal alloy comprises a stacking fault energy of at least about 50 mJ/m.sup.2, and the skin metal alloy comprises iron, aluminum, and boron.

A precipitation hardenable, cobalt-nickel base superalloy is disclosed. The is characterized by the following weight percent composition. C about 0.01 to about 0.15 Cr about 6.00 to about 15.00 Ni about 30.00 to about 45.00 W about 3.00 to about 15.00 Ti about 0.50 to about 4.00 Al about 3.00 to about 7.00 Nb up to about 2.50 Ta up to about 6.00 Hf up to about 1.50 Zr up to about 1.50 B up to about 0.20 Mo up to about 2.50 Si up to about 1.50
The balance of the alloy is cobalt and usual impurities. The alloy provides a novel combination of strength and ductility after long-term exposure to elevated operating temperatures as found in gas turbines and jet engines. A fine-grain steel article made from the alloy is also disclosed. The steel article is also characterized by a continuous surface layer of Al.sub.2O.sub.3 and Cr.sub.2O.sub.3 that protects the alloy from oxidation at the elevated operating temperatures.

A precipitation hardenable, cobalt-nickel base superalloy is disclosed. The is characterized by the following weight percent composition. C about 0.01 to about 0.15 Cr about 6.00 to about 15.00 Ni about 30.00 to about 45.00 W about 3.00 to about 15.00 Ti about 0.50 to about 4.00 Al about 3.00 to about 7.00 Nb up to about 2.50 Ta up to about 6.00 Hf up to about 1.50 Zr up to about 1.50 B up to about 0.20 Mo up to about 2.50 Si up to about 1.50
The balance of the alloy is cobalt and usual impurities. The alloy provides a novel combination of strength and ductility after long-term exposure to elevated operating temperatures as found in gas turbines and jet engines. A fine-grain steel article made from the alloy is also disclosed. The steel article is also characterized by a continuous surface layer of Al.sub.2O.sub.3 and Cr.sub.2O.sub.3 that protects the alloy from oxidation at the elevated operating temperatures.

The invention relates to a method for producing molded bodies from a silicon alloy, comprising the production of plates and the water jet cutting of the plates to form a plurality of molded bodies. The thus obtained molded bodies contain in particular additional inoculant additives and are used in particular as inoculant for metal casting.

The invention relates to a method for producing molded bodies from a silicon alloy, comprising the production of plates and the water jet cutting of the plates to form a plurality of molded bodies. The thus obtained molded bodies contain in particular additional inoculant additives and are used in particular as inoculant for metal casting.

Methods and compositions are provided for improving metal dusting corrosion, abrasion resistance and/or erosion resistance for various materials, preferably for applications relating to high-temperature reactors, including dense fluidized bed reactor components. In particular, cermets comprising (a) at least one ceramic phase selected from the group consisting of metal carbides, metal nitrides, metal borides, metal oxides, metal carbonitrides, and mixtures of thereof and (b) at least one metal alloy binder phase are provided. Ceramic phase materials include chromium carbide (Cr.sub.23C.sub.6). Metal alloy binder phase materials include β-NiAl intermetallic alloys and Ni.sub.3Sn.sub.2 intermetallic alloys, as well as alloys that contain α-Cr and/or γ′-Ni.sub.3Al hard phases. Preferably, bimetallic materials are provided when the cermet compositions are applied using a laser, e.g., a laser cladding method such as high power direct diode (HPDD) laser, or by plasma-based methods such as plasma transfer arc (PTA) welding and powder plasma welding (PPW).

The present invention relates to a protective layer against CMAS, to a CMAS-resistant article comprising the protective layer according to the invention, and to a process for preparing a corresponding article.