In as much as MIM parts manufacturing is not a "one-size fits all" solution, many times DSH partners with other companies interested in developing turnkey solutions for all aspects of the MIM parts producing process.
Below are a the areas where we excel at providing customers with custom tailored solutions:
The type of feedstock you use depends on many elements, including
- The quantity, size, and complexity of the part
- The part geometry
- The alloy and starting powders you will be using
- The volume of feedstock needed
- Whether you will make or buy your feedstock
We can help you choose the best feedstock for your application and tailor it to your requirements.
The correct tool design is critical in MIM. This includes using the correct shrinkage, and the proper positioning of gates, runners, venting, slides, and parting lines. DSH can analyze your tool design before cutting any metal by performing a mold flow analysis. While this may seem like an additional expense, the costs are much lower than multiple tool modifications based on trial and error.
We can help you in designing the optimum tool for the part that you want to mold.
Molding is one of the most critical steps throughout the entire MIM process. Understanding the parameters of injection molding can be challenging. If any variable is over looked or not addressed, this could result in poorly produced MIM parts. It is at this step that critical quality checkpoints need to be taken, because if problems are discovered, the poorly produced green parts may be reground and reused depending on the type of feedstock.
We can help you analyze your current molding parameters, provide education of proper quality procedures and review your injection molding steps for optimization.
Primary Debinding: Solvent, Catalytic or Water Debinding
The choice of feedstock determines the method to be used for removing the primary binder. Removal of the primary binders open up pores through which the secondary binders may escape later.
Wax Based – Solvent Debinding
Polyacetal Based – Catalytic Debinding
Water Soluble Based – Water Debinding
We can help you choose the right feedstock for your product and the equipment for processing it.
Secondary Thermal Debinding and Sintering
The secondary debinding and sintering are carried out in the same furnace in a single step. After the secondary debinding is completed, the furnace ramps on to the sintering temperature and sinters the parts.
The secondary or backbone binder holds the metal or alloy particles together until the powders start bonding by diffusion. The binder must be removed without leaving residues in the part in the form of carbon or other inorganic materials to ensure that the composition of the powder is not contaminated or compromised.
The binder must also be removed in a manner slow enough so not to crack or distort the part by the force of the binder material leaving the part. The debind hold must be long enough to remove all the binders.
At the end of the secondary debinding, when all the binders are removed from the part, the interparticle necks formed are very fragile the part is not strong enough to be handled. The temperature may be now ramped up to the sintering temperature to sinter the parts.
During sintering, when temperatures are as high as 0.8 times the melting point of the material in degrees Celsius, the bond between the particles form and grow in most cases by the mechanism of solid state diffusion. This leads to the elimination of pores and causes the shrinkage and densification of the part.
The final size of the part depends on the powders used, the binder content of the feedstock, and the shrinkage factor of the feedstock as well as the processing and sintering parameters.
We can help you choose the right equipment, processing and sintering parameters for your material to produce the part that you want.
MIM part design is challenging enough to ensure the correct final properties will be achieved through the debinding and sintering process, but there is one major factor in play to ensure the final part meets its overall required properties and characteristics… How will the part be staged throughout its lifecycle???
Is your MIM part able to rest on a flat surface?
If not, how will you stage your part to ensure proper uniform shrinkage? Is it more cost effective to design a special setter or should you redesign the part?
Have you considered all the different types of setter materials and how it may impact the material characteristics of your MIM Part?
We can help design and have an optimum setter made for your part if you have such a requirement.
Testing for Carbon, Oxygen, Density & Metallographic Analysis
When you make a part, a key question is: does this part meet all the mechanical and chemical property requirements and industry standards? Often a few simple tests can answer these questions. At DSH we can help with testing the Carbon, Oxygen, Density and metallographic properties of your MIM part.
We can perform testing to determine how well the part has been sintered and whether you have an optimum process.
Special equipment is needed to study and ensure that the process is performing the way it was designed.
We can help you determine your needs and fulfill them.