From Implants to Smartphones: The Unexpected Journey of ASTM F75 in Metal Injection Molding

For decades, ASTM F75 was known almost exclusively as a biomedical alloy.

Originally developed for surgical implants, this cobalt–chromium–molybdenum (CoCrMo) material earned its reputation through exceptional wear resistance, corrosion stability, and biocompatibility. It became a standard material for orthopedic implants, dental restorations, trauma fixation systems, and high-load medical components worldwide.

But around 2016–2020, an unexpected transition began.

As consumer electronics evolved toward thinner structures, smaller mechanical architectures, and increasingly complex miniature assemblies, several high-end smartphone supply chains quietly started evaluating ASTM F75 through the Metal Injection Molding (MIM) process.

What once belonged almost entirely to the medical industry began appearing inside precision electronic devices.

Why Consumer Electronics Became Interested in ASTM F75

Modern smartphone structures face a difficult engineering balance:

• extremely limited internal space

• repeated mechanical stress

• miniaturized moving components

• strict dimensional tolerances

• long-term wear reliability

Conventional stainless steels and aluminum alloys could not always satisfy every requirement simultaneously.

ASTM F75 offered a unique combination of properties:

One representative application discussed within the MIM industry was miniature lens support and stabilization structures used in certain premium smartphone camera modules during the late 2010s.

Although these applications were rarely publicized openly by OEM supply chains, the material became one of the more interesting crossover cases between medical metallurgy and consumer electronics engineering.

The Rise of Advanced MIM Powder Technology

This transition would not have been possible without major advances in fine powder manufacturing.

Between 2015 and 2020, powder producers significantly improved:

• combined water–gas atomization technologies

• low-oxygen powder control

• particle size distribution consistency

• feedstock homogeneity

• impurity management

• sintering dimensional control

For MIM manufacturers, ASTM F75 was never an easy alloy.

Compared with standard stainless MIM materials like 316L or 17-4PH, CoCrMo systems presented far more complex processing challenges:

1. Oxygen Sensitivity

Cobalt-based alloys are highly sensitive to oxygen pickup during atomization and sintering.

Excess oxygen can severely affect:

• ductility

• density

• fatigue behavior

• surface finish quality

Maintaining low oxygen content became essential for high-end miniature applications.

2. Silicon Inclusion Control

Microscopic inclusions from atomization and powder handling could directly impact polishing performance and structural reliability.

For smartphone camera-related structures, even minor defects could create assembly or optical alignment issues.

3. Sintering Deformation

ASTM F75 has a relatively narrow process window during MIM sintering.

Manufacturers had to carefully balance:

• shrinkage consistency

• carbon control

• grain growth

• dimensional repeatability

This became especially difficult for ultra-small precision geometries.

4. Large-Scale Consistency

Producing laboratory-grade parts is one challenge.

Producing millions of dimensionally stable miniature components with repeatable quality is an entirely different engineering problem.

This period pushed many powder suppliers and MIM factories to significantly improve process control capabilities.

The Cobalt Problem: When Material Economics Changed

Technically, ASTM F75 performed extremely well.

But engineering performance alone does not determine long-term material adoption.

Around 2020, global cobalt demand increased dramatically due to rapid expansion in:

• electric vehicles (EVs)

• lithium-ion batteries

• energy storage systems

• renewable energy infrastructure

According to the International Energy Agency, global demand for battery-related critical minerals accelerated sharply during this period, with cobalt becoming one of the most strategically sensitive materials in modern manufacturing.

Cobalt prices became increasingly volatile, and supply chain pressure intensified.

As a result, some consumer electronics applications gradually shifted away from ASTM F75 toward:

• aluminum alloys

• stainless steel alternatives

• titanium-based systems

• hybrid structural designs

Importantly, this transition was not necessarily caused by technical failure.

In many cases, ASTM F75 still offered superior mechanical performance.

The shift happened because modern material selection increasingly depends on:

• raw material availability

• geopolitical supply risk

• manufacturing scalability

• cost stability

• cross-industry resource competition

This is one of the clearest examples of how supply chain economics can reshape engineering decisions.

Why ASTM F75 Still Matters Today

Even today, ASTM F75 remains extremely difficult to replace in applications where reliability outweighs raw material cost.

The alloy continues to play a critical role in:

• orthopedic implants

• surgical systems

• dental applications

• high-wear precision mechanisms

• aerospace wear components

• specialized industrial tooling

Its unique balance of:

• hardness

• corrosion resistance

• fatigue performance

• biocompatibility

• wear stability

still makes it one of the most respected cobalt-based engineering alloys in powder metallurgy.

More Than a Medical Alloy

The story of ASTM F75 is not simply about metallurgy.

It is about how materials migrate between industries as technology evolves.

A biomedical implant alloy unexpectedly entered the world of smartphones.
A material designed for hip joints found new life inside miniature precision electronics.
And later, battery supply chains reshaped its commercial future once again.

Sometimes the most interesting material stories are not about invention.

They are about adaptation.

And ASTM F75 remains one of the most fascinating examples of how advanced materials move across industries in ways nobody originally expected.