Casting porosity can be removed post cast.

From this

To this

  Before

  • Eliminates all internal voids in castings and metallic components created by additive manufacturing methods
  • Decreases casting inspection rejection rate
  • Improves product consistency
  • Improves soundness and mechanical properties (fatigue life, ductility, impact strength) of castings, potentially allowing sleeker design
  • Enhances vacuum tightness and machined surface finish of castings
  • Produces full density material from metal, composite, polymer or ceramic powders without melting
  • From powders, creates solid material with superior properties due to fine, uniform grain size and isotropic structure
  • Enables unique powder blends to be combined into solids that would not be possible to form by other manufacturing methods
  • Produce complex-shaped solid components from powders
  • Improves toughness, ductility, fatigue strength, and consistency of metal injection moulded (MIM) parts
  • Bonds dissimilar metals without the need of temperature-limiting adhesives
  • Produce clad components via HIP bonding.

after

  • HIP improves product consistency with less variation in mechanical properties.
  • Typically tensile and proof strengths increase by around 5% and ductility by up to 50%, although the degree of casting property improvement is dependent on many parameters including the initial as cast quality.
  • Fatigue properties significantly increase following HIP with up to tenfold fatigue life improvements achieved, producing properties comparable to similar wrought alloys.
  • Impact strength, toughness, and machined surface finish are all enhanced.
  • Property improvements may allow castings to be considered for new applications and/or allow a redesign of existing components to a more cost effective solution.
  • Shrinkage defects, creep voids and internal cracks are removed.
  • HIP allows recovery of castings that would otherwise be rejected based on x-ray inspection.
  • By eliminating porosity, HIP removes fatigue crack initiation sites

Here are just some of the materials that can be treated:-

Peek thermo plastic
Magnesium
Aluminum Alloys
Copper
Copper based alloys
Gun metals
Titanium
Steels
Superalloys
Cobalt Chrome
Stellites
Tungsten carbides
Ceramics

Most cast products suffer from porosity whether it be micro or serious voids sub surface. Once machined the porosity is evident and the casting either needs weld repair or is scrap. Valves with important sealing surfaces with sub surface porosity can leak under pressure. By including our Argon high pressure treatment these sub surface voids are collapsed and a superior machined sealing surface is achieved. Contact us for a call back and we will discuss how we can help.
  
By incorporating this high pressure process into your casting route, time wasted through xray in minimised. You supply your casting post fettled in a clean condition and we will treat them at typical temperatures of :-

Magnesium < 500°c
Aluminium Alloys ~ 500°c
Titanium ~900 °c
Copper ~ 950°c
Steel ~ 1100°c
Superalloys 1160 - 1235°c
Tungsten Carbide - 1330 - 1390°c
Ceramics - ~ 1400°c

Argon gas pressures vary up to 200Mpa. This is 30,000 psi which is equivalent to 12.4 tons of gas pressure on every surface, even inside the cooling channels of turbine blades. This is isostatic hot argon gas pressure which does not distort the casting, merely squeezes it for the porosity to consolidate. Non surface connected porosity will be eradicated under normal conditions.

The Mariana_Trench which is the deepest part of the oceans on earth has a pressure of 15,750 psi (1086 bar). A standard high pressure hot argon gas cycle subjects the casting to 15,400 psi (1030 bar) so consider your casting to have seen the equivalent of being at the btm of the Mariana trench but also at an elevated temperature customed to suit the material.

The effects of this treatment are not reproduceable in any other process, all internal voids will be closed.


Also available for:-

Metal matrix composites
Supplying powder billets
Removing surface connected porosity
Bonding sputter targets
Diffusion bonding of dissimilar metals.
Powder cladding.
Turbine blade rejuvenation

Removing porosity from castings

All casting can suffer from some sort of porosity, providing it is not surface connected then we can process it to remove it. Surface connected can be closed by weld and then treated to some extent. Why not contact us to see what we can do for you. . Argon treatment leaves no residues. Not only does it close porosity but it also improves the properties of the casting, a 2 in 1 process.

 

 

                      

Before.jpg (6745 bytes)

After.jpg (5846 bytes)

email us to find out more and how we can help you.

As the pressure medium is Argon gas, there is no contamination of the workpiece. Most Argon is recycled as there are minimul impurities. Typically less than 50 parts per million in total of the gases  ( HC, H2, 02, H20 and N2 )

If you have problems with porosity then contact me in the first instance and we will help you have the porosity removed from your castings.

Maximum weight of 12 tons can be processed in one cycle ( dimensions permitting) with state of the art equipment and most  major aerospace approvals.

Powder billets can be manufactured on site to supply a 100% dense product in any powder ( aluminium alloys, copper, titanium, tool steel, Stellite, superalloys and carbides.


The above is an extreme example of how high pressure Argon, temperature and time influence
how porosity reacts within a casting.Our process was able to remove a 30mm pore,
normally micro or macro porosity is the norm.

Avoid a void and have your castings routinely treated to our process  email porosity@littlemesters.com

email porosity@littlemesters.com