4 major issues of PIM Technology

In the late 90s, there were nearly 300 PIM factories running around the world. However, the real problem is slowly emerging, how to solve the following 4 issues became the key to PIM!

1 defect control: how can we eliminate weld marks, cracks, voids, and other defects?

2 improve process yield: when you form a yield of only 80%, it is difficult to be profitable.

3 dimensional control: as far as possible to achieve the same size, the same shape of the product.

4 carbon control: bonding agent is very easy to pollute the product, so it is difficult to achieve the specific requirements of the carbon content of heat treatment steel; therefore, even today, low carbon stainless steel is very difficult to do it out of PIM.

What are the criteria for PIM binder selection?

After a long period of exploration, it was found that the key factor of PIM was the selection of adhesive. Powderinjection molding (PIM) of the binder should at least meet the 5 conditions:

1 in molding temperature, the additive is usually a short polymer filler, has a lower viscosity;

2 in the heating process, to maintain the same shape of green polymer backbone;

3 small molecular weight, avoid residual stress and deformation, easy to combine with the surface of solid powder;

4 the surface of the solid powder can be ensured to have good wetting property with the auxiliary agent, so that it can be combined well and not easily separated;

5 the price is not expensive, environmental protection, low water absorption.

Introduction to MIM and PIM

MIM began at the end of 1970s, including product design, mold design, mold design, quality testing, mixing, injection, skim, sintering, two processing, such as 8 important links. With the continuous development of the research and the development of new binder, flour milling technology and the continuous progress of the process, to the beginning of the 90's has been realized. Currently, MIM has been hailed as' one of the world's most popular metal parts forming technology '.

PIM can manufacture of disposable many complex shapes difficult molding parts, such as a variety of external cutting groove, external thread, the tapered outer surface, cross holes, blind holes, grooves and key pin, strengthen rib plate, surface knurling. In addition, the technology can realize automatic continuous operation, the production efficiency is high, and the material utilization rate is almost 100%. And due to the traditional methods of production of tungsten and molybdenum powder with fine particle size by MIM process does not need to increase the cost of raw material powder, so that the tungsten and molybdenum products have significant economic benefits.