Claims:CLAIMS

We Claim

1. A three-way catalyst substrate (10) manufactured by means of a functionally graded material, the three-way catalyst substrate (10) comprising:
a metal-based portion (12) facing an engine and adapted to receive exhaust gas that is discharged from said engine;
a ceramic-based portion (14) facing away from the engine and adapted to receive exhaust gas that is discharged from said engine and that flows past the metal-based portion (12); and
a metal-ceramic portion (16) sintered between the metal-based portion (12) and the ceramic-based portion (14), the metal-ceramic portion (16) containing a heterogenous mixture of metal particles and ceramic particles that are combined together in a known proportion such that a concentration of the metal particles decreases from the metal-based portion (12) towards the ceramic-based portion (14), and concentration of the ceramic particles decreases from the ceramic-based portion (14) towards the metal-based portion (12).

2. The three-way catalyst substrate (10) manufactured by means of a functionally graded material in accordance with Claim 1, wherein the metal-based portion (12) facing the engine has a length along the three-way catalyst substrate (10) which can be varied based on user-defined application.

3. The three-way catalyst substrate (10) manufactured by means of a functionally graded material in accordance with Claim 1, wherein the ceramic-based portion (14) facing away from the engine has a user-defined length along the three-way catalyst substrate (10).
4. The three-way catalyst substrate (10) manufactured by means of a functionally graded material in accordance with Claim 1, wherein a length of the metal-ceramic portion (16) sintered between the metal-based portion (12) and the ceramic-based portion (14) is pre-determined by a user based on a user specific application.

5. The three-way catalyst substrate (10) manufactured by means of a functionally graded material in accordance with Claim 1, wherein the metal-ceramic portion (16) containing the heterogenous mixture of metal particles and ceramic particles that are combined together in a known proportion is pre-determined by a user based on the user specific application.

6. The three-way catalyst substrate (10) manufactured by means of a functionally graded material in accordance with Claim 1, wherein the metal-ceramic portion (16) sintered between the metal-based portion (12) and the ceramic-based portion (14) is created by one of a chemical vapor deposition technique, a laser sintering technique, a thermal spraying technique, an electrophoretic deposition technique, a powder metallurgy technique, a sedimentation technique, a gel casting technique, and a tape casting technique. The size of the particles and the distribution of the particles along the length of the media can be altered linearly, parabolically, hyperbolically as per the application requirement pre-determined by the user. , Description:Complete Specification:

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the invention
[0001] This invention relates to a three-way catalyst substrate, and more specifically to a three-way catalyst substrate that is manufactured by means of a functionally graded material which is a biomimetic material.

Background of the invention
[0002] JP 2003193168 A2 describes a functionally graded composite material having various excellent properties, such as strength, hardness, and toughness, and also to provide its manufacturing method. A compact having a hole part is produced from a powder mixture containing metal particles and ceramic particles, and sintering treatment is applied to the compact to form a porous sintered compact. A metallic core material, whose surface is coated with carbon black and h-BN, is inserted into the hole part of the porous sintered compact, which is immersed in a solution containing catalytic metal. Then the sintering treatment is applied again. By this procedure, the porous sintered compact can be densified, and metallic elements can be allowed to diffuse from the metallic core material, and further, the metallic core material and a body part can be joined to each other to form a punch as the functionally graded composite material.

Brief description of the accompanying drawing
[0003] Figure 1 illustrates a three-way catalyst substrate that is manufactured by means of a functionally graded material which is a biometric material.

Detailed description of the embodiments
[0004] A three-way catalyst substrate 10 manufactured by means of a functionally graded material is described. The three-way catalyst substrate 10 comprises a metal-based portion 12 facing an engine and adapted to receive exhaust gas that is discharged from the engine. A ceramic-based portion 14 faces away from the engine and is adapted to receive exhaust gas that is discharged from the engine and that flows past the metal-based portion 12. A metal-ceramic portion 16 is sintered between the metal-based portion 12 and the ceramic-based portion 14. The metal-ceramic portion 16 contains a heterogenous mixture of metal particles and ceramic particles that are combined in a known proportion such that a concentration of the metal particles decreases from the metal-based portion 12 towards the ceramic-based portion 14, and a concentration of the ceramic particles decreases from the ceramic-based portion 14 towards the metal-based portion 12.

[0005] A three-way catalyst substrate 10 manufactured by means of a functionally graded material is described. In an exemplary embodiment, the three-way catalyst substrate 10 comprises a metal-based portion 12. The metal-based portion 12 of the three-way catalyst substrate 10 faces an exhaust gas flow path of an engine and is adapted to receive exhaust gas that is discharged from the engine. A ceramic-based portion 14 of the three-way catalyst substrate 10 faces away from the exhaust gas flow path of the engine and is adapted to receive exhaust gas that is discharged from the engine. More specifically, the exhaust gas that is discharged from the engine flows past the metal-based portion 12 of the three-way catalyst substrate 10 that faces the engine and is then allowed to flow on to the ceramic-based portion 14 of the three-way catalyst substrate 10 that faces away from the exhaust gas flow path of the engine.

[0006] In an exemplary embodiment, a metal-ceramic portion 16 is sintered between the metal-based portion 12 and the ceramic-based portion 14 of the three-way catalyst substrate 10. The metal-ceramic portion 16 contains a heterogenous mixture of metal particles and ceramic particles that are combined in a known proportion such that a concentration of the metal particles decreases from the metal-based portion 12 towards the ceramic-based portion 14. Similarly, a concentration of the ceramic particles decreases from the ceramic-based portion 14 towards the metal-based portion 12. More specifically, since the metal-ceramic portion 16 contains a heterogenous mixture of metal particles and ceramic particles that are combined together in a known proportion, the reduction in the concentration of the metal particles from the metal-based portion 12 towards the ceramic-based portion 14 can be precisely controlled based on the user specific application. Similarly, since the metal-ceramic portion 16 contains a heterogenous mixture of metal particles and ceramic particles that are combined in a known proportion, the reduction in the concentration of the ceramic particles from the ceramic-based portion 14 towards the metal-based portion 12 can be precisely controlled based on the user specific application.

[0007] In an exemplary embodiment, once the metal-ceramic portion 16 is sintered between the metal-based portion 12 and the ceramic-based portion 14, a coating of a catalyst material is applied on the metal-based portion 12 and the ceramic-based portion 14 respectively. More specifically, the coating of the catalyst material is higher on the metal-based portion 12 in contrast with the coating of the catalyst material that is applied on the ceramic-based portion 14.

[0008] In an exemplary embodiment, the ceramic-based portion 14 of the three-way catalyst substrate 10 faces away from the engine. The presence of the ceramic-based portion 14 of the three-way catalyst substrate 10 enhances the vibration and the thermal stability of the three-way catalyst substrate 10. However, the metal-based portion 12 of the three-way catalyst substrate 10 has better thermal conductivity characteristics in contrast with that of the ceramic-based portion 14 of the three-way catalyst substrate 10. Though metal-based substrate has better thermal conductivity, the ceramic-based portion 14 of the three-way catalyst substrate 10 enhances the vibration and the thermal stability of the three-way catalyst substrate 10. Thus a combination of metal-ceramic substrate is preferred.

[0009] In an exemplary embodiment, once the ceramic-based portion 14 of the three-way catalyst substrate 10 is combined with the metal-based portion 12 of the three-way catalyst substrate 10, a length of the metal-ceramic portion 16 that is sintered between the metal-based portion 12 and the ceramic-based portion 14 is pre-determined by a user based on a user specific application. In addition, when the pure metal-based portion 12 of the three-way catalyst substrate 10 is combined with the pure ceramic-based portion 14 of the three-way catalyst substrate 10, the metal-ceramic portion 16 at the interface of the metal-based portion 12 and the ceramic-based portion 14 of the three-way catalyst substrate 10 containing the heterogenous mixture of metal particles and ceramic particles are combined together in a proportion that is pre-determined by the user based on the user specific application. Therefore, by varying the heterogenous mixture of metal particles and ceramic particles that are combined in a known proportion that is pre-determined by the user, the composition of the metal-ceramic portion 16 of the three-way catalyst substrate 10 can be suitably altered.

[0010] In an exemplary embodiment, the metal-ceramic portion 16 sintered between the metal-based portion 12 and the ceramic-based portion 14 of the three-way catalyst substrate 10 is created by one of a chemical vapor deposition technique, a laser sintering technique, a thermal spraying technique, an electrophoretic deposition technique, a powder metallurgy technique, a sedimentation technique, a gel casting technique, and a tape casting technique.

[0011] A working of the three-way catalyst substrate 10 manufactured by means of a functionally graded material is described as an example. When the engine is started up, the exhaust gas from the engine flows through the metal-based portion 12 of the three-way catalyst substrate 10. Since, metal is a good conductor of heat, the exhaust gas heats the metal-based portion 12 of the three-way catalyst substrate 10 faster than the ceramic-based portion 14 of the three-way catalyst substrate 10 that is located at the opposite end of the metal-based substate 12 and faces away from the engine. Therefore, the exhaust gas that heats the metal-based portion 12 of the three-way catalyst substrate 10 causes the light off temperature of the catalyst to be attained faster. Since the light off temperature of the catalyst of the metal-based portion 12 of the three-way catalyst substrate 10 is attained faster, the catalyst that is coated on the metal-based portion 12 of the three-way catalyst substrate 10 becomes active and starts to reduce the pollutants from the engine.

[0012] The time taken for the light off temperature of the catalyst in the metal-based portion 12 of the three-way catalyst substrate 10 to be attained is expected to be lower than the time taken for the light off temperature of the catalyst in the ceramic-based portion 14 of the three-way catalyst substrate 10 to be attained. Therefore, from the time when the engine is started, until the point when light off temperature is attained in the metal-based portion 12 of the three-way catalyst substrate 10, the catalyst does not reduce the exhaust gas that flows over the metal-based portion 12 of the three-way catalyst substrate 10. As soon as the light off temperature is attained in the metal-based portion 12 of the three-way catalyst substrate 10, the catalyst that is coated on the metal-based portion 12 of the three-way catalyst substrate 10 begins reducing the exhaust gas pollutants that flow over the metal-based portion 12 of the three-way catalyst substrate 10. The time taken for the light off temperature to be attained from the time when the engine is started is expected to be lower by using the metal-based portion 12 of the three-way catalyst substrate 10 that is sintered to the ceramic-based portion 14 of the three-way catalyst substrate 10.

[0013] It must be understood that the embodiments explained above are only illustrative and do not limit the scope of the disclosure. Many modifications in the embodiments with regard to dimensions of various components are envisaged and form a part of this invention. The scope of the invention is only limited by the scope of the claims.