A method of diffusion bonding metal or metal alloy containing workpieces, comprises (a) coating the bonding surfaces of the metal or metal alloy containing workpieces with a layer of a coating material, (b) abrading the coated bonding surfaces to remove surface oxide, the coating material being in liquid form, (c) removing excess coating material or excess abraded metal or metal alloy containing workpiece material from the coated bonding surfaces, and (d) diffusion bonding the coated bonding surfaces of the metal or metal alloy containing workpieces together. The coating material is operable to form a stable barrier on the bonding surfaces of the metal or metal alloy containing workpieces under ambient conditions, and evaporates from the bonding surfaces under diffusion bonding conditions. There is also a bonded workpiece formed using the method of diffusion bonding metal or metal alloy containing workpieces.

The method comprises applying a spot load to a joint part between a first metal material and a second metal material in a state where sites to form the joint part are superposed on each other. When a total thickness of the first metal material and the second metal material at the joint part before bonding is defined as T.sub.0 mm, the total thickness thereof after bonding is defined as T.sub.1 mm, and T.sub.0/T.sub.1=R is defined as a reduction ratio, the reduction ratio R is 1.4 or more.

The method comprises applying a spot load to a joint part between a first metal material and a second metal material in a state where sites to form the joint part are superposed on each other. When a total thickness of the first metal material and the second metal material at the joint part before bonding is defined as T.sub.0 mm, the total thickness thereof after bonding is defined as T.sub.1 mm, and T.sub.0/T.sub.1=R is defined as a reduction ratio, the reduction ratio R is 1.4 or more.

A method for manufacturing a shaft (1) in which linking members (3) are provided to ends of a cylindrical member (2) including: polishing end surfaces of a metal sheet; a bending step for bending the metal sheet into a cylindrical or arcuate shape; butting together the polished end surfaces of the metal sheet, the end surfaces facing each other in a state in which the metal sheet has been bent into the cylindrical shape, or disposing a plurality of the metal sheets that are bent into an arcuate shape so as to form a cylindrical shape and butting together the polished end surfaces of the metal sheets, and then heating the butted portions so that the butted portions are diffusion-joined, thereby forming the cylindrical member (2); cooling the post-diffusion-joining-step cylindrical member (2); and joining the linking members (3) to the ends of the cylindrical member (2).

A titanium product includes an inner layer portion and a surface layer portion joined to the inner layer portion. The surface layer portion has a composition consisting of, by mass %, O: 0.4% or less, Fe: 0.5% or less, Cl: 0.020% or less, the balance: Ti and impurities. The inner layer portion 3 has pores and a composition consisting of, by mass %, O: 0.4% or less, Fe: 0.5% or less, Cl: more than 0.020% and 0.60%, the balance: Ti and impurities. The area fraction of the pores in the inner layer portion in a cross-section perpendicular to the longitudinal direction of the titanium product is more than 0% and not more than 30%. The Cl content (Cl.sub.I) of the inner layer portion, a thickness (t.sub.S) of the surface layer portion, and a thickness (t.sub.I) of the inner layer portion satisfy the expression [Cl.sub.I≤0.03+0.02×t.sub.S/t.sub.I].

An article comprises a first portion comprising a first alloy and a second portion comprising a second alloy that is metallurgically bonded to the first portion to form a monolithic article. The metallurgical bonding involves the application of an electrical current across the bond line and results in a retention of a metallurgical structure of the first portion and of a metallurgical structure of the second portion immediately adjacent to a bond line. The first portion has a first dominant property and the second portion has a second dominant property. The first dominant property is different from the second dominant property. The first dominant property is selected to handle operating conditions at a first position of the article where the first portion is located and the second dominant property is selected to handle operating conditions at a second position of the article where the second portion is located.

An article comprises a first portion comprising a first alloy and a second portion comprising a second alloy that is metallurgically bonded to the first portion to form a monolithic article. The metallurgical bonding involves the application of an electrical current across the bond line and results in a retention of a metallurgical structure of the first portion and of a metallurgical structure of the second portion immediately adjacent to a bond line. The first portion has a first dominant property and the second portion has a second dominant property. The first dominant property is different from the second dominant property. The first dominant property is selected to handle operating conditions at a first position of the article where the first portion is located and the second dominant property is selected to handle operating conditions at a second position of the article where the second portion is located.

Exemplary methods of cooling a semiconductor component substrate may include heating the semiconductor component substrate to a temperature of greater than or about 500° C. in a chamber. The semiconductor component substrate may be or include aluminum. The methods may include delivering a gas into the chamber. The gas may be characterized by a temperature below or about 100° C. The methods may include cooling the semiconductor component substrate to a temperature below or about 200° C. in a first time period of less than or about 1 minute.

Exemplary methods of cooling a semiconductor component substrate may include heating the semiconductor component substrate to a temperature of greater than or about 500° C. in a chamber. The semiconductor component substrate may be or include aluminum. The methods may include delivering a gas into the chamber. The gas may be characterized by a temperature below or about 100° C. The methods may include cooling the semiconductor component substrate to a temperature below or about 200° C. in a first time period of less than or about 1 minute.

It is an object to provide a method for producing a substrate for epitaxial growth having a higher degree of biaxial crystal orientation without forming an irregular part a3. The method for producing a substrate for epitaxial growth comprising a step of laminating a metal base material and a copper layer having an fcc rolling texture by surface-activated bonding, a step of applying mechanical polishing to the copper layer, and a step of carrying out orientation heat treatment of the copper layer, wherein the copper layer is laminated in such a way that, when ratios of the (200) plane of the copper layer before laminated and of the copper layer after laminated when measured by XRD are I0.sub.Cu and I0.sub.CLAD, respectively and ratios of the (220) plane of the copper layer before laminated and of the copper layer after laminated are I2.sub.Cu and I2.sub.CLAD, respectively, I0.sub.Cu<20%, I2.sub.Cu=70 to 90%, and I0.sub.CLAD<20%, I2.sub.CLAD=70 to 90% and I0.sub.CLAD−I0.sub.Cu<13%.