Hitachi, Ltd.

Tomio Umino

Tomohiko Shida

Munenobu Suzuki

Tomio Iizuka

Ryutarou Jimbou

Shoji Isobe

A laser beam reflection system for applying a laser beam to an area to be treated. The laser beam reflection system has a hollow head housing, first reflecting mirror means disposed in the rotary head housing and adapted to deflect the laser beam introduced into the rotary head housing away from the axis, second reflecting mirror means disposed in the rotary head housing and adapted to reflect the laser beam coming from the first reflecting mirror means to such a direction as to traverse the axis, and third reflecting mirror means disposed in the head housing movably in the direction traversing the axis and adapted to reflect and focus onto the area the laser beam coming from the second reflecting mirror means. The laser beam reflection system of the invention can be used for welding, surface treatment, heat treatment, cutting of various materials, and a light source of laser communication systems.

Laser beam reflection system

In a process for fusion-welding a binary combination of an iron alloy containing 50 % by weight or less of nickel and cobalt combined and copper; or a ternary combination of said iron alloy, copper, and iron, including the steps of bringing members of said binary combination or ternary combination into gapless contact with one another and subjecting the contact zone to a treatment including at least one of electron beam welding, laser beam welding, plasma welding, and TIG welding without use of a filler metal, an improvement which is characterized by supplying welding energy necessary to form in the welding zone molten weld metal having such a width and depth that have been determined from the composition and thickness of said base metals so that the composition of the weld metal may fall within the specified area in a diagram, shown in FIG. 1, representing composition of a three component system, said specified area being enclosed with straight lines connecting successively the point X (97 wt-% Cu, 2 wt-% Fe, 1 wt-% Ni + Co), the point Y (2 wt-% Cu, 49 wt-% Fe, 49 wt-% Ni + Co), the point Z (2 wt-% Cu, 97 wt-% Fe, 1 wt-% Ni + Co), and the point X except for the area enclosed with straight lines connecting successively the point a (35 wt-% Cu, 32.5 wt-% Fe, 32.5 wt-% Ni + Co), the point b (10 wt-% Cu, 45 wt-% Fe, 45 wt-% Ni + Co), the point c (8 wt-% Cu, 91 wt-% Fe, 1 wt-% Ni + Co), the point d (45 wt-% Cu, 54 wt-% Fe, 1 wt-% Ni + Co), and the point a. According to this improved process, development of weld cracking can be prevented.

Process for fusion-welding iron-nickle-cobalt alloy and copper or said

A method for welding copper or a copper base alloy and iron or an iron base alloy characterized in that an element for enhancing the mutual miscibility of copper and iron and an element for refining the crystal grains of the weld metal is added to weld metal in a total amount of 1 to 25 percent by weight based on the weld metal, thereby preventing the welded portion from crack formation and segregation.

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Hitachi, Japan

Tomio Umino