Titanium composite material and titanium material for hot working
Provided is a titanium composite material 1 including: a first surface layer portion 2 ; an inner layer portion 4 ; and a second surface layer portion 3 ; wherein: the first surface layer portion 2 and the second surface layer portion 3 are composed of a titanium alloy; the inner layer portion 4 is composed of a commercially pure titanium including pores; a thickness of at least one of the first surface layer portion 2 and the second surface layer portion 3 is 2 μm or more, and a proportion of the thickness with respect to an overall thickness of the titanium composite material 1 is 40% or less; and a porosity in a cross section perpendicular to a sheet thickness direction is more than 0% and 30% or less.
1. A titanium composite material comprising:
a first surface layer portion;
an inner layer portion; and
a second surface layer portion;
wherein:
the first surface layer portion and the second surface layer portion consist of a titanium alloy;
the inner layer portion consists of a commercially pure titanium including pores;
a thickness of at least one of the first surface layer portion and the second surface layer portion is 2 μm or more, and a proportion of the thickness with respect to an overall thickness of the titanium composite material is 40% or less; and
a porosity in a cross section perpendicular to a sheet thickness direction is more than 0% and 2.1% or less.
2. The titanium composite material according to claim 1 , wherein
at least one of the first surface layer portion and the second surface layer portion has a chemical composition comprising, by mass %:
platinum group elements: 0.01 to 0.25%,
rare earth elements: 0 to 0.2%,
Co: 0 to 0.8%,
Ni: 0 to 0.6%, and
a balance: Ti and impurities.
3. The titanium composite material according to claim 2 , wherein:
the platinum group elements are Pd and/or Ru.
4. The titanium composite material according to claim 2 , wherein
the chemical composition contains, by mass %:
rare earth elements: 0.001 to 0.2%.
5. The titanium composite material according to claim 2 , wherein
the chemical composition contains, by mass % one or more elements selected from:
Co: 0.05 to 0.8%, and
Ni: 0.05 to 0.6%.
6. The titanium composite material according to claim 1 , wherein
the commercially pure titanium has a chemical composition comprising, by mass %,
C: 0.1% or less,
H: 0.015% or less,
O: 0.4% or less,
N: 0.07% or less,
Fe: 0.5% or less, and
a balance: Ti and impurities.
7. The titanium composite material according to claim 3 , wherein
the chemical composition contains, by mass %:
rare earth elements: 0.001 to 0.2%.
8. The titanium composite material according to claim 3 , wherein
the chemical composition contains, by mass % one or more elements selected from:
Co: 0.05 to 0.8%, and
Ni: 0.05 to 0.6%.
9. The titanium composite material according to claim 4 , wherein
the chemical composition contains, by mass % one or more elements selected from:
Co: 0.05 to 0.8%, and
Ni: 0.05 to 0.6%.
10. The titanium composite material according to claim 7 , wherein
the chemical composition contains, by mass % one or more elements selected from:
Co: 0.05 to 0.8%, and
Ni: 0.05 to 0.6%.
11. The titanium composite material according to claim 2 , wherein
the commercially pure titanium has a chemical composition comprising, by mass %,
C: 0.1% or less,
H: 0.015% or less,
O: 0.4% or less,
N: 0.07% or less,
Fe: 0.5% or less, and
a balance: Ti and impurities.
12. The titanium composite material according to claim 3 , wherein
the commercially pure titanium has a chemical composition comprising, by mass %,
C: 0.1% or less,
H: 0.015% or less,
O: 0.4% or less,
N: 0.07% or less,
Fe: 0.5% or less, and
a balance: Ti and impurities.