Metal 3D Printing vs. Metal Injection Molding – The Differences Between Additive Manufacturing & Metal Injection Molding

Overview Of What Is Metal Injection Molding 

Metal injection molding is a powdered metal process that enables you to create these highly complex shapes, then mass produces them, utilizing these inexpensive metal powders. this technique uses a wide variety of part sizes from very small to some medium-sized parts. it has widely accepted validated standards(ASTM & ISO standards). it’s used across a broad variety of different industries(metals: everything from stainless steels to even titanium, copper materials). 

The Disadvantages Of Metal Injection Molding

With all traditional manufacturing methods, there are some challenges in this industry. most of these challenges come around the extensive tooling costs. you need these very expensive molds that generally are costing you ten to even a hundred thousand dollars per mold for each different geometry you want to make. with those molds, comes with an 8 to 20 week lead time. it takes some highly skilled dedicated operators to produce these molds, it’ll require a lot of work, a very long lead time, and a very high part cost.

Metal Injection Molding Challenges

Due to the high cost of these mold investments, we’re only using metal injection molding for very high volumes of parts. because you need to amortize hundreds of thousands even millions of parts over that entire mold cost. since investments have been made in the mold, part designs will be relatively locked. don’t make any changes to its geometry, because it requires changes to molds as well that way, then you’ll have to invest more money and time into the parts. looking at metal engine molding, long lead times, 8 to 20 weeks to get up running, large non-recurring engineering costs in both the design of the tooling as well as fabrication. you need these highly skilled dedicated operators to design the molds. it’s a very industrial process, most companies do not do metal injection molding in their facilities, they have to send it out to an external vendor. there are quite a few geometry limitations on your parts because of the constraints of what can be molded. 

The Results of MIM (Metal Injection Molding)

There are months before it can bring to a production line – from when your part design is complete to when it can start being produced, that’s due to that tool creation. it’s a lot less design iteration customization. because once you’ve designed your part, you’re locked into your manufactured tool. and you’re often sacrificing design optimization for ease of manufacturing and bending to the will of your manufacturing method. there are far more concerns about how the parts can be molded easily than about the optimized geometry for the application. there’s a need to only produce in high quantities because you’re looking to amortize that mold cost.

The challenges’ results of metal injection molding are true for almost all traditional manufacturing methods, like casting machining, forging, stamping, or sheet metal applications they all have the same challenges and results. and the solutions for these challenges of traditional manufacturing have two major themes. Let’s take a look!

Metal 3D Printing As A Complement To Metal Injection Molding

We’re looking at low volume when we’re talking about metal 3D printing as a complement to metal injection molding. the prototypes, jigs, fixtures, tooling, pilot runs, anything that you can print in metal will help assist your metal injection molding parts that you’re already creating. maybe you’re putting some prototypes of that part before you invest in the tool to ensure we’re getting the optimized design.

Prototyping/Pilot Runs/Low Volume Production

With 3D printers, you’re now able to print functional metal parts affordably and quickly during the development stage. no longer do I have to bother my machinists to machine these parts or maybe I’m prototyping in plastic in the past, but a plastic part is only good for form and fit. now you can validate parts in the actual assembly and machine to understand how that geometry will perform. the parts can withstand high loading, high heat, corrosion environments to do functional prototyping, not just form and fit as you do in plastic. another advantage of this is the ability to produce larger parts. metal injection molding does have some limitations with how large your parts can get, but with the Metal 3D Printing process, we’re able to build larger parts.