METHOD OF PRODUCING SiC-Si COMPOSITE COMPONENT AND SiC-Si COMPOSITE COMPONENT

Abstract

wherein the content of Si is in the range of 5% by mass to 40% by mass in the SiC—Si composite component.

1 . A method of producing a SiC—Si composite component comprising:
 preparing a first molded body containing SiC particles by a 3D printing method, wherein the first molded body has a first average pore diameter M 1 ; 
 forming a second molded body, in which the first molded body and a dispersion containing carbon particles are brought into contact so that the pores are impregnated with the carbon particles, wherein the carbon particles have a secondary particle having an average particle diameter M 2 , and the carbon particles satisfy the following formula:
     M   2   ≤M   1 /10; and 
 
 forming a SiC—Si composite component by carrying out that the second molded body is impregnated with a metallic Si and is reactively sintered; 
 wherein the content of Si is in the range of 5% by mass to 40% by mass in the SiC—Si composite component. 
 
     
     
         2 . The method according to  claim 1 , wherein the first molded body is brought into contact with the dispersion containing carbon particles when the second molded body is formed. 
     
     
         3 . The method according to  claim 1 , wherein the first average pore diameter M 1 is in the range of 20 μm to 100 μm. 
     
     
         4 . The method according to  claim 1 , wherein the SiC particles have an average particle size in the range of 30 μm to 200 μm. 
     
     
         5 . The method according to  claim 1 , wherein the average particle diameter M2 is in the range of 100 nm to 200 nm. 
     
     
         6 . The method according to  claim 1 , wherein a content of the carbon particles in the dispersion is in the range of 20% by mass to 60% by mass. 
     
     
         7 . The method according to  claim 1 , wherein the first molded body is prepared by inkjet printing a binder on a powder layer containing the SiC particles. 
     
     
         8 . The method according to  claim 7 , wherein the powder layer further contains a curing agent. 
     
     
         9 . The method according to  claim 1 , wherein
 drying the second molded body after the second molded body is formed.   
     
     
         10 . The method according to  claim 9 , wherein the second molded body is vacuum freeze-dried. 
     
     
         11 . The method according to  claim 1 , wherein the second molded body is impregnated with a molten metallic Si when SiC—Si composite component is formed. 
     
     
         12 . The method according to  claim 1 , wherein forming the SiC—Si composite component under the coexistence of the metallic Si and the second molded body at a temperature equal to or higher than a melting point of the metallic Si. 
     
     
         13 . The method according to  claim 1 , wherein the SiC—Si composite component obtained has a bulk density of 2.79 g/cm 3  or more. 
     
     
         14 . A SiC—Si composite component comprising:
 a sea-island structure containing α-SiC particles having an average particle size of 30 μm to 200 μm, β-SiC particles having an average particle size of 1 μm to 20 μm, and a metallic Si, 
 wherein the metallic Si is configured as a sea portion of the sea-island structure, and a first island portion formed from the α-SiC particles and a second island portion formed from the β-SiC particles are placed in the sea portion configured by the metallic Si. 
 
     
     
         15 . The SiC—Si composite component according to  claim 14 , wherein at least a part of the second island portion is configured by connecting a plurality of the β-SiC particles to each other. 
     
     
         16 . The SiC—Si composite component according to  claim 15 , wherein when a cross-section of the SiC—Si composite component is photographed at magnification of 20 times, a ratio P obtained by the following procedure is 3 or more:
 drawing a circle having a diameter of 200 μm with any of the β-SiC particles as a center in the second island portion formed by connecting the plurality of β-SiC particles to each other; 
 drawing a first straight line having a length of 200 μm and passing through the center of the circle; 
 drawing a second straight line having a length of 200 μm and having a rotation angle of 1° with respect to the first straight line with the center as a central axis in the circle; 
 drawing total 180 straight lines in the circle in the same manner as the above until the rotation angle reaches 180°; 
 measuring each length of a line segment of one or a plurality of straight line which across the sea portion, and calculating an average value S ave  of the length of the line segment in each straight line; 
 selecting a straight line in which the average value S ave  becomes maximum from the 180 straight lines and set as maximum S max , selecting a straight line in which the average value S ave  becomes minimum from the 180 straight lines and set as minimum S min , and calculating the ratio P by the following formula:
     P=S   max   /S   min    (1).
 
 
 
     
     
         17 . The SiC—Si composite component according to  claim 14 , wherein a total content of the α-SiC particles and the β-SiC particles is 60% by mass or more and 95% by mass or less. 
     
     
         18 . The SiC—Si composite component according to  claim 14 , wherein a ratio of a volume of the α-SiC particles to a volume of the β-SiC particles (α-SiC/β-SiC) is 0.5 to 10. 
     
     
         19 . The SiC—Si composite component according to  claim 14 , wherein a ratio of a volume of the β-SiC particles to a volume of the metallic Si (β-SiC/metallic Si) is 0.4 to 12. 
     
     
         20 . The SiC—Si composite component according to  claim 14 , wherein a thermal conductivity is 200 W/m·K or more.