A kind of boat and boat assembly used for cemented carbide dewaxing process

Abstract

The invention discloses a boat and boat group for a hard alloy dewaxing process. The boat for the hard alloy dewaxing process comprises a bottom plate and a side wall; the side wall is enclosed at the outer edge of the obverse side of the bottom plate; more than one horizontal flow guide slot and more than one longitudinal flow guide slot are formed in the obverse side of the bottom plate; the horizontal flow guide slots are intersected with the longitudinal flow guide slots, and bottom plate through holes are formed in the bottom plate at the intersections; and more than one side wall through hole is formed in the side wall. The boat group comprises a cover plate and more than two groups of boats for the hard alloy dewaxing process, the boats are vertically stacked, and the cover plate covers the side wall of the boat located at the topmost layer. The boat and boat group for the hard alloy dewaxing process, disclosed by the invention, have the advantages of high dewaxing efficiency, stable product quality and the like.

Description

technical field [0001] The invention relates to the technical field of metal forming, in particular to a boat and a boat set used in a cemented carbide dewaxing process. Background technique [0002] Cemented carbide is an alloy material made of hard compounds of refractory metals and bonding metals through powder metallurgy. Cemented carbide has a series of excellent properties such as high hardness, wear resistance, good strength and toughness, heat resistance and corrosion resistance. Cemented carbide production needs to go through two processes of mixture pressing and compact sintering. In order to facilitate product pressing and molding, a certain amount of PEG (polyethylene glycol) or paraffin will be added to the mixture, and PEG or paraffin needs to be removed in the sintering process. . [0003] There are two kinds of boat sets commonly used at present: one is an open boat set, such as figure 1 As shown, there is no sidewall around the first boat 8 used by this b...

AI Technical Summary

Problems solved by technology

[0003] There are two kinds of boat sets commonly used at present: one is an open boat set, such as figure 1 As shown, there is no sidewall around the first boat 8 used by this boat group, when the first boat 8 is stacked, graphite pillars or other supports 9 are placed on the four corners of the first boat 8, and then Place the first boat 8 on the upper layer on the support 9. When this kind of boat group is dewaxed, the flow direction of the internal atmosphere is disordered, and the removal of wax vapor is not smooth; the other is a closed boat group, such as figure 2 As shown, there are side walls around the second boat 10 used, and a sealed boat group is formed after the second boat 10 is stacked. When this boat group is dewaxed, because the inside is in a sealed state, it is severely restricted. The flow of the dewaxing atmosphere, when dewaxing products with large size and high forming agent content, the internal wax vapor cannot be eliminated, resulting in dewaxing defects in the product

In addition, in the above-mentioned two structures of boat sets, the front of the boat substrate is flat, and the product is completely in contact with the boat, which will cause the dewaxing of the bottom of the product to be difficult, especially for some larger volumes or the contact surface with the boat. For larger products, product dewaxing will be more difficult, causing product hole defects or even crack defects, resulting in unstable product quality

[0004] For example, the Chinese patent document CN201010586416.8 discloses a graphite boat and a graphite boat group used in the cemented carbide sintering process. A sealed boat group is constructed by using a perforated boat. The exchange of airflow improves the uniformity of the temperature field inside the boat group, but because the inside of the boat group is sealed, it is not conducive to the flow of dewaxing atmosphere, which seriously hinders the dewaxing of large-scale products

Chinese patent document CN201110100741.3 discloses a multipurpose boat and a multipurpose boat set for powder metallurgy sintering. Put the long strip-shaped powder metallurgy sintered body to avoid the product from being dumped and damaged during transportation and sintering. However, because the product is placed in the groove, some products will also be placed above the through hole to block the discharge of wax vapor, resulting in the diversion The concentration of wax vapor around the product in the tank increases, which will also affect the dewaxing process of the product

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