Hot Isostatic Pressing Densal®®

Why Densal®?

Aluminium casting offers the opportunity to produce cost-effective complicated net-shape components regardless of casting technique or the alloy composition used. Gas and shrinkage-porosity can exist in the castings, negatively influencing the mechanical properties of the component.

By removing this porosity, Densal® improves the performance of aluminium castings which are subjected to high dynamic loads, such as are seen in performance-critical applications.

What does Densal® deliver?

  • Increased mechanical strength
  • Longer fatigue life
  • Uniform mechanical properties
  • Pore-free machined surfaces
  • Reduced property scatter
  • Improved x-ray inspection acceptance
  • Enhanced surface finish

When to use Densal®?

  • Aluminium castings subject to dynamic loads
  • Critical parts made from aluminium alloys
  • Components where surface finish is important
  • Cosmetic, ornamental and decorative castings

Aluminium densification

Bodycote offers Hot Isostatic Pressing, a casting densification service specifically for aluminium to remove porosity and increase the performance of aluminium alloys. Among these is Densal®, exclusively offered by Bodycote.

Designed, tested, proven

After several years of trials and verifications within the automotive industry, Bodycote’s team of technical experts developed the Densal® process. Since its launch, Densal® has been adopted and integrated into the production processes of major OEMs and their Tier 1 suppliers. It has successfully improved aluminium components and generated cost savings for the supply chain.

Using Densal® in combination with best practice foundry techniques result in a significant improvement in the mechanical properties of cast parts compared to parts without Densal® treatment, producing high quality, porosity-free cast aluminium components.

Hot Isostatic Pressing Densal®®

Automotive and general industrial market segments

Densal® can be used for aluminium components across a variety of market sectors to significantly improve mechanical properties, corrosion resistance, surface finish and aesthetic appearance.

Hot Isostatic Pressing Densal®®

Applications suited for Densal®

Aluminium castings are used widely in the automotive market for modern, high-performance engines. Ever increasing performance requirements for these engine components, such as crankcases, mean that the material must perform near to the limit of it’s capability, elevating the risk of failure. For several years, Bodycote has processed crankcases and the data from as-cast and Densal® processed components have been compared through laboratory and real-world testing. As a result of this comparison, major OEMS have firmly integrated Densal® into the production process of these crankcases.

With Densal® components show

  • Significant increase in service life
  • Narrower scatter band of properties
  • Failure probability significantly reduced

For applications in the high performance motorsports market for NASCAR, Formula 1 and Le Mans racing cars, adding the Densal® process to manufacturing specifications leads to:

  • Reduced weight
  • Enhanced performance
  • Higher mechanical strength
  • Increased life of components

For the automotive markets the improved consistency of properties together with significant increase in fatigue performance improves reliability, i.e. fewer premature failures, and enables maximum efficiency, i.e. reduce weight and increase stress limits.

Fatigue life improvement with Densal®

Fatigue test results of samples taken from crankcase castings show that Densal® increases fatigue life by a factor of 10.

Hot Isostatic Pressing Densal®®

Before and after Densal®

Without Densal®

Machining an aluminium alloy casting exposes porosity resulting in a poor surface finish.

With Densal®

No porosity results in improved surface finish.

Hot Isostatic Pressing Densal®®

Typical Results

Typical results for investment and sand cast alloy when comparing the as-cast components to those that have been processed with Densal®.

Hot Isostatic Pressing Densal®®

Case Studies


A Tier 1 supplier to a European-based automotive manufacturer sought higher performance and reduced scrap rate from its cast engine blocks. The Densal® process increased performance levels by 10 times, lowered the scrap rate, and improved surface finish. The Densal® process is now specified as an engine program requirement.


A North American motorcycle manufacturer needed a solution which improved the finish for cast wheels and trim. These cast components showed porosity after machining. Bodycote’s Densal® process effectively treated the porosity so that the wheels and trim held a high gloss finish after machining.


A European supplier of retail fuel pumps needed a solution to reduce its scrap rate and remove the porosity from the fuel pipes when the pipes were machined. Densal® helped remove the porosity and reduce the scrap rate from 40% to 4%.

A prerequisite for successful Densal® processing is that the porosity should not be surface connected, or contain high internal gas pressure. The best results are attained by processing un-machined, sand, investment or permanent mould castings with undamaged casting surfaces.

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