The demand for strong, lightweight, complex shaped components has been growing across industries over the past decade, from aerospace, to consumer electronics. That’s not a surprise with its ability to produce intricate parts in a variety of metals, including steel, stainless steel, and high-temperature alloys.
If you’re interested in learning more about the MIM process, you’re in the right place. Below, we discuss the step-by-step process, along with the advantages and disadvantages of the technology.
Metal injection molding is a technology that combines plastic injection molding and powdered metallurgy to produce complex parts that wouldn’t be possible with traditional machining methods.
For a better picture of the actual process, we’ll break down the process into four steps, including:
The MIM process begins with feedstock preparation, where fine metal powder is blended with thermoplastic and wax binders. The blend is heated, causing the binders to melt. The material is mechanically mixed until all the metal powder particles are uniformly distributed within the binder. The mass is then cooled and granulated into feedstock that can be used in the MIM machine.
If you’re familiar with plastic injection molding, you’ll have a good grasp of how MIM works. First, the feedstock is placed into the MIM machine, where it’s heated and injected into a mold cavity under high pressure. The ‘green’ part is then allowed to cool and removed from the mold so the process can be repeated.
The part is now ready to move onto the debinding, or binder removal process. The majority of debinding takes place prior to sintering, leaving behind just enough binder to handle the parts into the furnace. After debinding, the part will be semi-porous, which allows the remaining binder to escape during the sintering process.
During the sintering process, the brown parts are loaded into a high temperature, atmosphere controlled sintering furnace, where they are slowly heated to evaporate the remainder of the binders. Once all of the binders have been released, the component is heated, where it shrinks, transforming into a dense solid.
What's All the Hype About?
There’s a lot to be excited about when it comes to MIM. The technology has the ability to create parts for half of the cost of machining or investment casting. Not only that, MIM can:
Sounds great, right? Before you make a decision, it’s also important to check out the disadvantages too. Disadvantages of MIM include:
If you’re looking for a process that can manufacture high volumes of small, intricate parts, MIM may be a good fit for you. On the other hand, if you’re running smaller quantities of parts, a different technology may be more cost effective for you.
For further information, contact one of our experts.