Multi-material connecting rod
A sintered powder metal connecting rod has (i) a central beam section made of a stronger material and (ii) crank and piston end sections made of more machinable materials, and may be forged or not.
1 . A connecting rod comprising:
a central beam section comprising a first sintered material having a first chemical composition and a first density, the first sintered material having a first tensile strength, and the first sintered material having a first machinability;
a first end integrally connected to the beam section; and
a second end integrally connected to the beam section opposite the first end, the second end comprising a second sintered material uniform throughout the second end, the second sintered material having a second chemical composition different from the first chemical composition, the second sintered material having a second density different from the first density, the second sintered material having a second tensile strength lower than the first tensile strength, and the second sintered material having a second machinability higher than the first machinability.
2 . The connecting rod of claim 1 wherein:
the first end comprises a third sintered material uniform throughout the first end, the third sintered material having a third chemical composition different from the first chemical composition, the third sintered material having a third density different from the first density, the third sintered material having a third tensile strength lower than the first tensile strength, and the third sintered material having a third machinability higher than the first machinability.
3 . The connecting rod of claim 2 wherein:
the second sintered material and the third sintered material are the same.
4 . The connecting rod of claim 2 wherein:
the second sintered material and the third sintered material are different.
5 . The connecting rod of claim 2 wherein:
the first sintered material has a first zone comprising the first chemical composition and a second zone comprising a fourth chemical composition different from the first chemical composition.
6 . The connecting rod of claim 2 wherein:
the first sintered material has a first zone comprising the first density and a second zone comprising a fourth density different from the first density.
7 . The connecting rod of claim 1 wherein:
the first density is greater than the second density.
8 . The connecting rod of claim 1 wherein:
a material interface between the first sintered material of the beam section and the second sintered material of the second end is smooth.
9 . The connecting rod of claim 1 wherein:
the first tensile strength is in the range of 1400-1900 MPa and the second tensile strength is in the range of 700-1100 MPa.
10 . The connecting rod of claim 1 wherein:
the first sintered material has a hardness in the range of HRC 40-50, and the second sintered material has a hardness in the range of HRC 20-30.
11 . A connecting rod comprising:
a central beam section comprising a first sintered material having a first chemical composition, the first sintered material having a first tensile strength, and the first sintered material having a first machinability;
a first end integrally connected to the beam section; and
a second end integrally connected to the beam section opposite the first end, the second end comprising a second sintered material uniform throughout the second end, the second sintered material having a second chemical composition different from the first chemical composition, the second sintered material having a second tensile strength lower than the first tensile strength, and the second sintered material having a second machinability higher than the first machinability,
wherein a material interface between the first sintered material of the beam section and the second sintered material of the second end is smooth.
12 . The connecting rod of claim 11 wherein:
the first sintered material has a first density,
the second sintered material has a second density different from the first density, and
the first end comprises a third sintered material uniform throughout the first end, the third sintered material having a third chemical composition different from the first chemical composition, the third sintered material having a third density different from the first density, the third sintered material having a third tensile strength lower than the first tensile strength, and the third sintered material having a third machinability higher than the first machinability.
13 . The connecting rod of claim 12 wherein:
the second sintered material and the third sintered material are the same.
14 . The connecting rod of claim 12 wherein:
the second sintered material and the third sintered material are different.
15 . The connecting rod of claim 12 wherein:
the first sintered material has a first zone comprising the first chemical composition and a second zone comprising a fourth chemical composition different from the first chemical composition.
16 . The connecting rod of claim 12 wherein:
the first sintered material has a first zone comprising the first density and a second zone comprising a fourth density different from the first density.
17 . The connecting rod of claim 12 wherein:
the first density is greater than the second density.
18 . The connecting rod of claim 11 wherein:
the first tensile strength is in the range of 1400-1900 MPa and the second tensile strength is in the range of 700-1100 MPa.
19 . The connecting rod of claim 11 wherein:
the first sintered material has a hardness in the range of HRC 40-50, and the second sintered material has a hardness in the range of HRC 20-30.
20 . The connecting rod of claim 11 wherein:
the material interface is straight.