US 12,485,477 B1
Coarse grain cemented carbide and preparation method thereof
Yanyuan Tang, Chongyi (CN); Wei Zhong, Chongyi (CN); Qiumin Yang, Chongyi (CN); Yuan Zhong, Chongyi (CN); Zhiqiang Zhong, Chongyi (CN); Bangming Chen, Chongyi (CN); Bangwen Chen, Chongyi (CN); Haigen Xie, Chongyi (CN); and Enbiao Liu, Chongyi (CN)
Assigned to Chongyi Zhangyuan Tungsten Co., Ltd, Chongyi (CN)
Filed by Chongyi Zhangyuan Tungsten Co., Ltd, Chongyi (CN)
Filed on Nov. 11, 2024, as Appl. No. 18/943,572.
Claims priority of application No. 202410716602.0 (CN), filed on Jun. 4, 2024.
Int. Cl. B22F 1/05 (2022.01); B22F 3/10 (2006.01); B22F 3/105 (2006.01); C22C 1/051 (2023.01); C22C 29/08 (2006.01)
CPC B22F 1/05 (2022.01) [B22F 3/1007 (2013.01); B22F 3/105 (2013.01); C22C 1/051 (2013.01); B22F 2003/1051 (2013.01); B22F 2201/02 (2013.01); B22F 2302/10 (2013.01); B22F 2304/10 (2013.01); C22C 29/08 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A preparation method of grain cemented carbide, characterized in that comprising following steps;
S1, pretreating coarse grain tungsten carbide with a Fisher particle size above 30 μm; performing a dry ball milling process with a ball to material ratio of 1:2, of which time is 60-120 min; sieving the material by a 325-mesh sieve after ball milling; the pretreated coarse grain tungsten carbide is on sieve;
S2, putting a water-soluble cobalt salt, a nano fine grain tungsten carbide and the pretreated coarse grain tungsten carbide in a certain proportion in an agitating vessel; adding deionized water; stirring it to obtain a mixture; spray granulating the mixture to obtain a mixed material; wherein the mass ratio of the water-soluble cobalt salt, the nano fine grain tungsten carbide, and the coarse grain tungsten carbide is (5-10):(0.5-1.5):(88.5-94.5), with the amount of cobalt salt calculated on the basis of cobalt content;
S3, putting the mixed material in a mold; sintering it; the sintering proceeds in stages; S31, putting the mold containing the mixed material in a tube furnace for sintering; sintering temperature is 300-450° C.; sintering atmosphere is nitrogen; sintering time is 120-180 min; S32, putting the mold containing the mixed material sintered by S31 in the tube furnace for sintering; sintering temperature is 550-650° C.; sintering atmosphere is hydrogen; sintering time is 150-240 min; S33, putting the mold containing the mixed material sintered by S32 in a spark plasma sintering furnace for sintering; sintering temperature is 1500-1800° C.; sintering pressure is 15-25 MPa; sintering time is 3-8 min to obtain the cemented carbide.