Porous aluminum sintered compact and method of producing porous aluminum sintered compact
A high-quality porous aluminum sintered compact, which can be produced efficiently at a low cost; has an excellent dimensional accuracy with a low shrinkage ratio during sintering; and has sufficient strength, and a method of producing the porous aluminum sintered compact are provided. The porous aluminum sintered compact is the porous aluminum sintered compact ( 10 ) that includes aluminum substrates ( 11 ) sintered to each other. The junction ( 15 ), in which the aluminum substrates ( 11 ) are bonded to each other, includes the Ti—Al compound ( 16 ) and the Mg oxide ( 17 ). It is preferable that the pillar-shaped protrusions projecting toward the outside are formed on outer surfaces of the aluminum substrates ( 11 ), and the pillar-shaped protrusions include the junction ( 15 ).
1. A porous aluminum sintered compact comprising a plurality of aluminum substrates sintered to each other,
wherein a junction, in which the plurality of aluminum substrates are bonded to each other, includes a Ti—Al compound and a Mg oxide,
the plurality of aluminum substrates are made of aluminum fibers or both of aluminum fibers and an aluminum powder,
a ratio of the aluminum powder in the plurality of aluminum substrates is 15 mass % or less,
a plurality of pillar-shaped protrusions projecting toward an outside are formed on outer surfaces of the plurality of aluminum substrates, the pillar-shaped protrusions include the junction,
a porosity of the porous aluminum sintered compact is in a range of 56.5% or more and less than 90%, and
the aluminum fibers are subjected to a shape-added processing which is a torsion processing.
2. A method of producing the porous aluminum sintered compact according to claim 1 , the method comprising the steps of:
forming an aluminum raw material for sintering by adhering a titanium powder, which is made of any one of or both of a titanium metal powder and a titanium hydride powder, and a magnesium powder on outer surfaces of the plurality of aluminum substrates;
spreading the aluminum raw material for sintering on a holder; and
sintering the aluminum raw material held on the holder by heating, wherein
the plurality of aluminum substrates are bonded through a junction including a Ti—Al compound and the a Mg oxide.
3. The method of producing the porous aluminum sintered compact according to claim 2 , wherein the junction is formed on a plurality of pillar-shaped protrusions projecting toward an outside from outer surfaces of the plurality of aluminum substrates.
4. The method of producing the porous aluminum sintered compact according to claim 2 , wherein a content amount of the titanium powder in the aluminum raw material for sintering is set in a range of 0.01 mass % or more and 20 mass % or less, and a content amount of the magnesium powder in the aluminum raw material for sintering is set in a range of 0.01 mass % or more and 5 mass % or less in the step of forming an aluminum raw material for sintering.
5. The method of producing the porous aluminum sintered compact according to claim 2 , wherein the step of forming an aluminum raw material for sintering comprises the steps of:
mixing the plurality of aluminum substrates; and the titanium powder and the magnesium powder in a presence of a binder; and
drying a mixture obtained in the step of mixing.