Powder Blank Forming Method

Abstract

The invention discloses a powder billet forming device. The powder billet forming device comprises a die, an extruding rod, an amplitude-change pole and an energy converter, wherein the extruding rod is axially mounted in the die; one end of the amplitude-change pole is radially connected with the die, and the other end of the amplitude-change pole is connected with the energy converter; the electricity energy can be converted into mechanical vibration for driving the amplitude-change pole through the energy converter while axial pressure is applied to powder in the die through the extruding rod, and the die is driven to vibrate to apply radial pressure to the powder through the amplitude-change pole. The device is simple in structure, reliable in performance, and capable of quickly releasing the die; the powder is driven to vibrate through the die, so that the powder vibrating area is increased, and the powder can be uniformly vibrated, and as a result, the formed body density is improved, and the stress of the body is uniformly distributed. In addition, the invention also discloses a powder billet forming method.

Description

technical field [0001] The invention relates to the field of material processing and molding, in particular to a powder blank molding method. Background technique [0002] The main preparation process of powder metallurgy (Powder Metallurgy) and ceramic (Ceramic) includes powder preparation, blank forming and sintering. [0003] Compression molding is based on high pressure, which presses powdery blanks into block blanks in a mold. During the pressing process, the density, strength and pressure distribution in the green body will change due to the influence of external pressure on the billet. After the pressure is removed, the formed billet will be released from the die through the demoulding process, and then sintered after drying. [0004] Forming is to obtain a uniform and high-density green body material, which is an important link in powder metallurgy and ceramic preparation processes. Generally speaking, a green body with high uniformity, high density and near-net si...

AI Technical Summary

Problems solved by technology

Dry pressing is a kind of dry forming. Due to its high forming efficiency, precise size and low cost, it has become the preferred forming process for general structural ceramic products. However, due to its forming mechanism, there are always problems of density gradient and unevenness.

[0005] Therefore, some R&D personnel introduce ultrasonic vibration into the axial pressure rod, and apply vibration while the pressure rod is pressurized. To a certain extent, the internal equivalent stress distribution of the powder compact is more uniform, and the time required for the powder compact to be demoulded is reduced. The breakage of the compact due to the uneven distribution of internal stress reduces the loss of the compaction pressure along the axial direction and improves the density and uniformity of the powder compact. However, in the actual application process, there are the following problems: 1) In the extrusion rod Because the contact area between the pressing rod and the green body powder is too small, the ultrasonic vibration cannot be effectively and uniformly transmitted to the green body powder; 2) The ultrasonic vibration is gradually attenuated along the axial direction of the extrusion rod, and the density gradient and The problem of unevenness cannot be improved; 3) Applying vibration driving components on the extrusion rod makes the structure complex, the vibration mode is not reliable, and the efficiency is often low due to the limited pressure capacity of the transducer

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