Metal and Ceramic Micro Components Made by Powder Injection Molding

2007 ◽  
Vol 534-536 ◽  
pp. 373-376 ◽  
Author(s):  
Volker Piotter ◽  
G. Finnah ◽  
B. Zeep ◽  
Robert Ruprecht ◽  
Jürgen Haußelt
Keyword(s):  
Injection Molding ◽  
Large Scale ◽  
Ceramic Materials ◽  
Powder Injection Molding ◽  
Tungsten Alloy ◽  
Powder Injection ◽  
Scale Production ◽  
Large Scale Production ◽  
Scope Of Application ◽  
Tungsten Powders

To overcome the lack of micro manufacturing processes suitable for medium and large scale production as well as to process high resistive materials a special variant of micro injection molding is currently under development: micro powder injection molding (MicroPIM), which already enables the manufacturing of finest detailed components with structure sizes down to a few ten micrometer. In order to expand the scope of application of MicroPIM, tests are being conducted with pure tungsten powders or tungsten alloy powders. As further improvement, micro twocomponent injection molding allows, for example, the fabrication of micro components consisting of two ceramic materials with different physical properties.

Study on Binder System for Micro Powder Injection Molding of ZrO2 Ceramic

2012 ◽  
Vol 706-709 ◽  
pp. 1948-1954
Author(s):  
Lin Liu ◽  
X.L. Ni ◽  
Hai Qing Yin ◽  
Xuan Hui Qu
Keyword(s):  
Injection Molding ◽  
Large Scale ◽  
Dimensional Accuracy ◽  
Mold Filling ◽  
Powder Injection Molding ◽  
Powder Injection ◽  
Scale Production ◽  
Binder System ◽  
Widespread Application ◽  
Debinding Process

Micro powder injection molding has been accepted as a potential forming technology for large-scale production of miniature components in industries. However, mold filling capability is often poor due to the blind hole structure of the die cavity, which restricts the widespread application of this technique. In this paper, ZrO2 micro gears with addendum circle ranging from 900μm to 200μm were studied. Instead of using traditional PW-HDPE-SA binder as in powder injection molding, thermoplastic binder system is optimized here for better replication of micro gear. It is found that the dimensional accuracy and demold after injection molding can be improved by utilizing proper binder system. ZrO2 feedstock with a powder loading of 46vol.% and the binder system consisting of BW, HDPE and SA was successfully injection molded and demolded, which indicates good mold filling capability and sufficient demolding strength. The binder system was successfully removed by debinding process in two steps, solvent debinding followed by thermal debinding. Debound components free of defects were obtained. Keywords: Micro powder injection molding, ZrO2 feedstock, Binder system, Molding filling capability, Demolding strength

Advantages and Limitations of Using Nano Sized Powders for Powder Injection Molding Process: A Review

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Javad Rajabi ◽  
Norhamidi Muhamad ◽  
Abu Bakar Sulong ◽  
Abdolali Fayyaz ◽  
Azizah Wahi
Keyword(s):  
Injection Molding ◽  
Large Scale ◽  
Sintering Temperature ◽  
High Surface ◽  
Volume Ratio ◽  
Powder Injection Molding ◽  
Nano Particles ◽  
Powder Injection ◽  
Injection Molding Process ◽  
Molding Process

Powder injection molding (PIM) is among the most known forming techniques that use material powders. This technique has been widely evaluated for the production of large scale and small components using metal and ceramic powders. Nano particles have larger surface-to-volume ratio compared with large-sized particles, thus they display high surface area. Some merits in the application of nano-sized particles in the PIM process includes increasing its comparative density at a low sintering temperature, decreasing sintering temperature, decreasing grain size of sintered bodies, increasing hardness value, and improving surface properties. However, it also has several disadvantages, which include increasing the viscosity behaviour of feedstock, oxidation, and agglomeration. This article reviews current studies on the effects of nano-sized particles on the PIM process and finding solutions to address its disadvantages.

Critical Solid Loading and Rheological Study of WC-10%Co

2011 ◽  
Vol 52-54 ◽  
pp. 97-102 ◽  
Author(s):  
Heng Shye Yunn ◽  
Norhamidi Muhamad ◽  
Abu Bakar Sulong ◽  
Abdolali Fayyaz ◽  
Haw Pei Li
Keyword(s):  
Injection Molding ◽  
Large Scale ◽  
Variation Method ◽  
Powder Injection ◽  
Solid Loading ◽  
Flow Index ◽  
Flow Density ◽  
Scale Production ◽  
Micro Parts ◽  
Metallic Parts

Micro powder injection molding (µPIM) is a preferred technology for the production of micro parts or micro structured parts which derived from the well known thermoplastic injection molding technique. It is suitable for a large-scale production of ceramic and metallic parts without final machining. In the hardmetal industry, submicron and ultrafine hardmetals are the most demanding and also the fastest growing grades in production and application. Four stages involve in µPIM are mixing, injection, debinding and sintering. The volumetric ratio of solid powder to the total volume of powder and binder, which is usually called powder loading, largely determines the success or failure of subsequent processes. Critical solid loading of the powder can be estimated by torque variation, density, melt flow, density and viscosity versus composition. In this paper, critical solid loading of WC-10%Co is determined using torque variation method and its rheological behavior is studied. During the process, the wet surface of the powder particle WC-10%Co will cohesive together and resulted to the torque. Progressive powder is added-in after torque decrease and critical solid loading is identified when torque becomes unstable. Hence, critical solid loading WC-10%Co with WC (APS < 1 µm) is 46% and 42, 43 and 44 vol% of powder loading are selected to mix with wax-based binder system. The viscosity of feedstock show the pseudoplastic behavior and flow index (n) are 0.444, 0.491 and 0.492 for powder loading 42%, 43% and 44% respectively.

I. S. A. Baud. Forms of Production and Women's Labour: Gender Aspects of Industrialisation in India and Mexico. New Delhi: Sage Publications. 1992. 321 pp.Hardbound. Price: Indian Rs 295.00.

1993 ◽  
Vol 32 (1) ◽  
pp. 129-131
Author(s):  
Naureen Talha
Keyword(s):  
Large Scale ◽  
Indian Society ◽  
New Delhi ◽  
Scale Production ◽  
Female Labour ◽  
Self Employment ◽  
Commodity Production ◽  
Large Scale Production ◽  
Mexican Society ◽  
Small Production

The literature on female labour in Third World countries has become quite extensive. India, being comparatively more advanced industrially, and in view of its size and population, presents a pictures of multiplicity of problems which face the female labour market. However, the author has also included Mexico in this analytical study. It is interesting to see the characteristics of developing industrialisation in two different societies: the Indian society, which is conservative, and the Mexican society, which is progressive. In the first chapter of the book, the author explains that he is not concerned with the process of industrialisation and female labour employed at different levels of work, but that he is interested in forms of production and women's employment in large-scale production, petty commodity production, marginal small production, and self-employment in the informal sector. It is only by analysis of these forms that the picture of females having a lower status is understood in its social and political setting.

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