Method for jointing metal injection molded parts

Abstract

In a method for jointing metal injection molded parts, [1] at least two metal injection molded parts each of which is injection-molded from mixtures of metal powders and binders are contacted with each other, [2] paste agents containing nitrogen or chlorine are pasted on a jointed portion at which the at least two metal injection molded parts are contacted with each other, and [3] the at least two metal injection molded parts are jointed at the jointed portion by degreasing or sintering, and thereby a metal product is manufactured. According to the jointing method, jointing strength of the jointed portion can be improved.

What is claimed is: 
     
         1 . A method for jointing metal injection molded parts, the method comprising:
 contacting at least two metal injection molded parts with each other each of which is injection-molded from mixtures of metal powders and binders;   pasting paste agents containing nitrogen or chlorine on a jointed portion at which the at least two metal injection molded parts are contacted with each other; and   jointing the at least two metal injection molded parts at the jointed portion to manufacture a metal product by degreasing or sintering the at least two metal injection molded parts of which the jointed portion is pasted with the paste agents.   
     
     
         2 . The method for jointing metal injection molded parts according to  claim 1 , wherein
 the binders contain waxes that vapor at a predetermined temperature range, and plastics that disperse at a higher temperature range than the predetermined temperature range, and   part of the paste agents vapors later than the waxes and disperse earlier than the plastics during degreasing or sintering of the at least two metal injection molded parts.   
     
     
         3 . The method for jointing metal injection molded parts according to  claim 1 , wherein
 the paste agents are pasted on a contact surface or a circumferential side surface of the jointed portion.   
     
     
         4 . The method for jointing metal injection molded parts according to  claim 1 , wherein
 the at least two metal injection molded parts are degreased or sintered in a state where a gap of the jointed portion is kept not more than 0.1 mm.   
     
     
         5 . The method for jointing metal injection molded parts according to  claim 1 , wherein
 the metal product is a blade sector that includes a plurality of blades and a band portion that supports the plurality of blades, and   each of the at least two metal injection molded parts is a divided member of the blade sector, the divided member including a single blade.   
     
     
         6 . The method for jointing metal injection molded parts according to  claim 5 , wherein
 a rib that extends in a direction intersecting with a chord line of the blade is formed on a back surface, located on a back side of a surface on which the blade is raised, of the band portion.   
     
     
         7 . The method for jointing metal injection molded parts according to  claim 6 , wherein,
 when an angle between an extending direction of the band portion and an extending direction of the rib in the band portion is denoted by θ, the angle θ is larger than 0° and not larger than a stagger angle of the blade.   
     
     
         8 . The method for jointing metal injection molded parts according to  claim 6 , wherein,
 when an angle between an extending direction of the band portion and an extending direction of the rib in the band portion is denoted by θ, the angle θ satisfies 0°<θ≦12°.