Manufacturing of Net‐Shape Reaction‐Bonded Ceramic Microparts by Low‐Pressure Injection Molding

Abstract

Reaction‐bonded oxide ceramics based on intermetallic compounds are able to compensate the sintering shrinkage completely due to their high increase in volume caused by oxidation. Using low‐pressure injection molding (LPIM) for shaping ceramics avoids needless materials loss and affords the manufacturing of complex formed structures. The combination of both, reaction‐bonded ceramic and LPIM‐processing, offers the manufacturing of ceramic microparts by keeping a high accuracy and replication quality.

Impact of powder morphology on quality of low-pressure injection moulded reaction-bonded net shape oxide ceramics

“…1) was chosen as master model for an accuracy test pattern. 12 The replication quality was qualified by comparing the dimensions of the master model and the green body. The accuracy of the whole process was evaluated by comparing the dimensions of the master model and the sintered specimen.…”

“…[9][10][11] A combination of reaction-bonding net shape oxide ceramics and low-pressure injection moulding enables the economical production of ceramic micro devices with complex geometries and high aspect ratios. 12 The required powder content for feedstocks of reactionbonded net shape oxide ceramics to achieve zero shrinkage can be calculated as follows:…”

Overview of Injection Molding Technology for Processing Polymers and Their Composites

“…[10][11][12][13][14][15][16][17] There are also various forms of injection molding such as gas-assisted molding, waterassisted molding, micro-injection molding, injection foam molding, low-pressure molding, injection compression molding, etc. [18][19][20][21][22][23][24][25][26][27][28][29] The process of injection molding mainly includes three stages: three processes of filling, filling and holding. During the plasticizing stage of the injection process, the screw conveys the plasticized material forward at a certain speed.…”

Molding Properties of Inconel 718 Feedstocks Used in Low-Pressure Powder Injection Molding

“…Recent progress in feedstock formulations [2][3][4] has generated new opportunities for the injection of low-viscosity (<4 Pa⋅s) molten powder-binder mixtures (<100 ∘ C) into a mold cavity using an injection pressure generally lower than 700 kPa [5,6]. Initially used in ceramics forming [7][8][9], the LPIM technology has quickly become attractive for the development of high value-added metallic parts in the aerospace industry [10].…”