Method for bonding silicon carbide molded parts together or with ceramic or metal parts

Method of joining molded SiC ceramic parts with each other or with ceramic parts formed of other ceramic materials, or with metal pieces, comprising the steps of:

• preparing abrasively polished, clean surfaces to be joined respectively of a molded silicon carbide part and of a workpiece which is of a material selected from the group consisting of silicon carbide, ceramics other than silicon carbide and structural metals capable of keeping a clean untarnished metallic surface until the heating step set forth hereinbelow begins;
• interposing an alloy metal layer, of a thickness exceeding 3 .mu.m and not exceeding 1000 .mu.m, between said prepared surfaces to be joined and putting and holding said surfaces together while separated only by said alloy metal layer to produce a held-together assembly, said holding-together of said assembly being performed by mechanical pressure in the range from 0.5 to 60 MPa urging said prepared surfaces towards each other and said alloy metal having a base component combination selected from the group consisting of (a) manganese-copper alloys in the by-weight composition range of 10 to 90% copper content and (b) manganese-cobalt alloys in the by-weight composition range of 5 to 50% cobalt content, substantially all the remainder being in each case manganese including at least one alloy additive metal selected from the group consisting of chromium, titanium, zirconium, iron, nickel, vanadium and tantalum to an extent in which the total content of said additive metals in the said alloy metal does not exceed 70% by weight, the remainder being said alloy base and the content of any one of said alloy additive metals lies between 2 and 45% by weight of the alloy metal;
• and
• heating said held-together assembly in the absence of oxidizing gas for an interval not less than 5 or more than 50 minutes at a temperature lying from 20.degree. to 300.degree. C. below the melting point of said alloy metal, said temperature being high enough to produce diffusion-welding at said held-together surfaces, and thereby firmly joining said surfaces together, followed by cooling.

A method of joining molded SiC ceramic parts together or with ceramic parts containing free Si in their surfaces formed of other ceramic materials, or with metal pieces, comprising the steps of:

• preparing abrasively polished, clean surfaces to be joined respectively of a molded silicon carbide part and of a workpiece which is of a material selected from the group consisting of silicon carbide, ceramics other than silicon carbide and structural metals capable of keeping a clean, untarnished metallic surface until the heating step set forth hereinbelow begins;
• coating the prepared clean surface of said molded silicon carbide part with carbon black and thereafter heating it in the absence of reacting gas at a temperature between 900.degree. and 1450.degree. C. for a period from 10 to 150 minutes thereby converting free silicon of said prepared surface to silicon carbide;
• interposing an alloy metal layer, of a thickness exceeding 3 .mu.m and not exceeding 1000 .mu.m, between said prepared surfaces to be joined and putting and holding said surfaces together while separated only by said alloy metal layer to produce a held-together assembly, said alloy metal being selected from the group consisting of (a) manganese-copper alloys in the by-weight composition range of 10 to 90% copper and (b) manganese-cobalt alloys in the by-weight composition range of 5 to 50% cobalt content, substantially all the remainder in each case being manganese;
• and
• heating said held-together assembly in the absence of oxidizing gas to a temperature distinctly below the melting point of said alloy metal and high enough to produce diffusion-welding at said held-together surfaces and thereby firmly joining said surfaces together, followed by cooling.

A method of joining molded SiC ceramic parts containing free Si in their surfaces together or with ceramic parts formed of other ceramic materials, or with metal pieces, comprising the steps of:

• preparing abrasively polished, clean surfaces to be joined respectively of a molded silicon carbide part and of a workpiece which is of a material selected from the group consisting of silicon carbide, ceramics other than silicon carbide and structural metals capable of keeping a clean, untarnished metallic surface until the heating step set forth hereinbelow begins;
• heating said abrasively polished, clean surface of said molded silicon carbide part and said body on which it is prepared in nitrogen for a period of from 10 to 150 minutes at a temperature in the range from 900.degree. to 1450.degree. C. thereby converting free silicon of said prepared surface to silicon nitride;
• interposing an alloy metal layer, of a thickness exceeding 3 .mu.m and not exceeding 1000 .mu.m, between said prepared surfaces to be joined and putting and holding said surfaces together while separated only by said alloy metal layer to produce a held-together assembly, said alloy metal being selected from the group consisting of (a) manganese-copper alloys in the by-weight composition range of 10 to 90% copper and (b) manganese-cobalt alloys in the by-weight composition range of 5 to 50% cobalt content, substantially all the remainder in each case being manganese;
• and
• heating said held-together assembly in the absence of oxidizing gas to a temperature distinctly below the melting point of said alloy metal and high enough to produce diffusion-welding at said held-together surfaces and thereby firmly joining said surfaces together, followed by cooling.

A method of joining molded SiC ceramic parts containing free Si in their surfaces together or with ceramic parts formed of other ceramic materials, or with metal pieces, comprising the steps of:

• preparing abrasively polished, clean surfaces to be joined respectively of a molded silicon carbide part and of a workpiece which is of a material selected from the group consisting of silicon carbide, ceramics other than silicon carbide and structural metals capable of keeping a clean, untarnished metallic surface until the heating step set forth hereinbelow begins;
• heating said abrasively polished, clean surface of said molded silicon carbide part and said body having said clean surface in the presence of a carbon containing gas for a period having a duration between 10 and 150 minutes at a temperature in the range from 900.degree. to 1450.degree. C. for converting free silicon to silicon carbide;
• interposing an alloy metal layer, of a thickness exceeding 3 .mu.m and not exceeding 1000 .mu.m, between said prepared surfaces to be joined and putting and holding said surfaces together while separated only by said alloy metal layer to produce a held-together assembly, said alloy metal being selected from the group consisting of (a) manganese-copper alloys in the by-weight composition range of 10 to 90% copper and (b) manganese-cobalt alloys in the by-weight composition range of 5 to 50% cobalt content, substantially all the remainder in each case being manganese;
• and
• heating said held-together assembly in the absence of oxidizing gas to a temperature distinctly below the melting point of said alloy metal and high enough to produce diffusion-welding at said held-together surfaces and thereby firmly joining said surfaces together, followed by cooling.

A method of joining molded SiC ceramic parts containing free Si in their surfaces with each other or with ceramic parts formed of other ceramic materials, or with metal pieces, comprising the steps of:

• preparing abrasively polished, clean surfaces to be joined respectively of a molded silicon carbide part and of a workpiece which is of a material selected from the group consisting of silicon carbide, ceramics other than silicon carbide and structural metals capable of keeping a clean untarnished metallic surface until the heating step set forth hereinbelow begins;
• coating the prepared clean surface of said molded silicon carbide part with carbon black and thereafter heating it in the absence of reactive gas at a temperature between 900.degree. and 1450.degree. C. for a period from 10 to 150 minutes thereby converting free silicon of said prepared surface to silicon carbide;
• interposing an alloy metal layer, of a thickness exceeding 3 .mu.m and not exceeding 1000 .mu.m, between said prepared surfaces to be joined and putting and holding said surfaces together while separated only by said alloy metal layer to produce a held-together assembly, said alloy metal having a base component combination selected from the group consisting of (a) manganese-copper alloys in the by-weight composition range of 10 to 90% copper content and (b) manganese-cobalt alloys in the by-weight composition range of 5 to 50% cobalt content, substantially all the remainder being in each case manganese including at least one alloy additive metal selected from the group consisting of chromium, titanium, zirconium, iron, nickel, vanadium and tantalum to an extent in which the total content of said additive metals in the said alloy metal does not exceed 70% by weight, the remainder being said alloy base and the content of any one of said alloy additive metals lies between 2 and 45% by weight of the alloy metal;
• and
• heating said held-together assembly in the absence of oxidizing gas to a temperature distinctly below the melting point of said alloy metal and high enough to produce diffusion-welding at said held-together surfaces and thereby firmly joining said together, followed by cooling.

A method of joining molded SiC ceramic parts containing free Si in their surfaces with each other or with ceramic parts formed of other ceramic materials, or with metal pieces, comprising the steps of:

• preparing abrasively polished, clean surfaces to be joined respectively of a molded silicon carbide part and of a workpiece which is of a material selected from the group consisting of silicon carbide, ceramics other than silicon carbide and structural metals capable of keeping a clean untarnished metallic surface until the heating step set forth hereinbelow begins;
• heating said abrasively polished, clean surface of said molded silicon carbide part and said body on which it is prepared in nitrogen for a period of from 10 to 150 minutes at a temperature in the range from 900.degree. to 1450.degree. C. thereby converting free silicon of said prepared surface to silicon nitride;
• interposing an alloy metal layer, of a thickness exceeding 3 .mu.m and not exceeding 1000 .mu.m, between said prepared surfaces to be joined and putting and holding said surfaces together while separated only by said alloy metal layer to produce a held-together assembly, said alloy metal having a base component combination selected from the group consisting of (a) manganese-copper alloys in the by-weight composition range of 10 to 90% copper content and (b) manganese-cobalt alloys in the by-weight composition range of 5 to 50% cobalt content, substantially all the remainder being in each case manganese including at least one alloy additive metal selected from the group consisting of chromium, titanium, zirconium, iron, nickel, vanadium and tantalum to an extent in which the total content of said additive metals in the said alloy metal does not exceed 70% by weight, the remainder being said alloy base and the content of any one of said alloy additive metals lies between 2 and 45% by weight of the alloy metal;
• and
• heating said held-together assembly in the absence of oxidizing gas to a temperature distinctly below the melting point of said alloy metal and high enough to produce diffusion-welding at said held-together surfaces and thereby firmly joining said together, followed by cooling.

A method of joining molded SiC ceramic parts containing free Si in their surfaces with each other or with ceramic parts formed of other ceramic materials, or with metal pieces, comprising the steps of:

• preparing abrasively polished, clean surfaces to be joined respectively of a molded silicon carbide part and of a workpiece which is of a material selected from the group consisting of silicon carbide, ceramics other than silicon carbide and structural metals capable of keeping a clean untarnished metallic surface until the heating step set forth hereinbelow begins;
• heating said abrasively polished, clean surface of said molded silicon carbide part and said body having said clean surface in the presence of a carbon containing gas for a period having a duration between 10 and 150 minutes at a temperature in the range from 900.degree. to 1450.degree. C. for converting free silicon to silicon carbide;
• interposing an alloy metal layer, of a thickness exceeding 3 .mu.m and not exceeding 1000 .mu.m, between said prepared surfaces to be joined and putting and holding said surfaces together while separated only by said alloy metal layer to produce a held-together assembly, said alloy metal having a base component combination selected from the group consisting of (a) manganese-copper alloys in the by-weight composition range of 10 to 90% copper content and (b) manganese-cobalt alloys in the by-weight composition range of 5 to 50% cobalt content, substantially all the remainder being in each case manganese including at least one alloy additive metal selected from the group consisting of chromium, titanium, zirconium, iron, nickel, vanadium and tantalum to an extent in which the total content of said additive metals in the said alloy metal does not exceed 70% by weight, the remainder being said alloy base and the content of any one of said alloy additive metals lies between 2 and 45% by weight of the alloy metal;
• and
• heating said held-together assembly in the absence of oxidizing gas to a temperature distinctly below the melting point of said alloy metal and high enough to produce diffusion-welding at said held-together surfaces and thereby firmly joining said together, followed by cooling.