Hot Isostatic Pressing
Also known as: HIP
Hot Isostatic Pressing applies simultaneous high temperature (800–1250 °C depending on alloy) and isostatic pressure (100–200 MPa, argon atmosphere) to eliminate internal porosity and micro-cracks in AM metal parts. The combined thermo-mechanical driving force closes voids that form during LPBF or EBM solidification — achieving relative densities >99.95% and mechanical properties that approach or match wrought equivalents, particularly fatigue strength.
Why AM parts need this
LPBF and EBM parts contain 0.05–2% residual porosity (lack-of-fusion voids, keyhole pores, gas pores) even at optimised parameters. This porosity acts as a fatigue crack initiation site. For aerospace, medical implant, and fatigue-critical applications, HIP is mandatory — not optional. ASTM F3049 and AMS 7000 specify HIP as a required post-process for AM titanium alloy structural components.
Key parameters
Ti-6Al-4V: 895–940 °C (below beta transus). IN718: 1120–1185 °C. AlSi10Mg: 520–540 °C.
Wire-wound HIP vessels (Quintus) reach 200 MPa. Typical production runs: 100–150 MPa.
Longer holds improve densification of thick sections. Aerospace specs often mandate ≥2 h at temperature.
Rapid cooling (URC — Uniform Rapid Cooling, Quintus) allows HIP + quench in one cycle for titanium.
Compatible AM processes
Compatible materials
Limitations
- Does not eliminate surface porosity or surface-connected voids — only closed internal porosity closes
- Part dimensions change slightly (typically <0.2% linear shrinkage) — must be accounted for in near-net-shape design
- Rapid cooling HIP (URC) can substitute for separate stress-relief step but not for full precipitation hardening cycles in all alloys
- Not suitable for polymer AM parts
- Large-batch HIP furnaces (Bodycote, Quintus) have lead times of 2–6 weeks at commercial service bureaus
Related tools
Providers
Bodycote
World's largest provider of HIP, heat treatment, and surface technology services for AM and conventionally manufactured components.
Macclesfield, GB
Quintus Technologies
Swedish OEM of high-pressure industrial systems, including wire-wound HIP units optimised for closing porosity in AM parts.
Västerås, SE
Curtiss-Wright EST (Engineered Solutions & Technologies)
Canadian provider of HIP, heat treatment, and specialty metallurgical processing services for aerospace and nuclear AM components.
Cheswick, PA, CA
Solar Atmospheres
US vacuum heat treatment specialist operating NADCAP-accredited furnaces for stress relief, annealing, ageing, and brazing of AM titanium, nickel, and aluminium parts.
Souderton, PA, US
Wallwork Group
UK specialist in vacuum heat treatment, HIP, and PVD coating for aerospace and medical AM parts — NADCAP-accredited, Cambridge.
Cambridge, GB
ALD Vacuum Technologies
Hanau Germany vacuum metallurgy and heat treatment specialist — ALD furnaces for vacuum annealing, ageing, and HIP+heat-treat of LPBF titanium, nickel, and tool-steel AM components to aerospace specifications.
Hanau, DE
Seco/Warwick Group
Swiebodzin Poland — vacuum furnaces, fluidised bed furnaces, and VVPHT systems for AM post-processing heat treatment of aerospace titanium, nickel, and aluminium — serving EOS, SLM, and service bureau customers.
Swiebodzin, PL
Relevant standards
Parameter ranges from AMS 2801D, ASTM F3049, and published Quintus URC application notes. Cooling rate data from Quintus Technologies (manufacturer tier).
All post-processing