Uprights are a key-part for a racing car, and for everything with 4 wheels: in a F1 car for example the suspension fittings, the steering rod , the track rod and the brake calipers are connected to the uprights. 
The required properties are: lightness (as a non-suspended mass), stiffness (any deformation compromises the kinetics of the suspension and braking) and reliability, (as one of the safety components).
They were usually manufactured through a long and complicated forming and cutting of steel sheets process, which included welding, heat treatment, CNC machining and finally painting to protect against corrosion. This process can’t optimize the mechanical performances of the piece, making the uprights heavier than they should have been. Moreover, being a welded piece, it presents a structural anisotropy that shortens its lifespan, and therefore its reliability in time.
In 1998 CRP began to work alongside Minardi F1 team, helping it with the engineering process, manufacturing optimization and manufacturing process of front and rear uprights: they began from the study of the Rapid Casting process.

In 2000 was developed the Minardi Titanium Gearbox

After the titanium fabricated g/box (’97 Ferrari) and the carbon fiber case (’98 Arrows /’98 Stewart ), the Titanium Rapid Casting g/box was the latest evolution in this field and is currently one of the few providing such a high performance, as shown by the significant imitations following its introduction on the 2000 Minardi.

The requirements are the same as those for the uprights, however complexity for design and dimensions are far more important. Compared directly with a magnesium gearbox, weight saving is around 20-25% and dimension reduced by around 20%, torsional stiffness is double, gear wear is reduced, friction loss reduced, with possibility to run higher oil temperature and lower viscosity.

is based on the combination of Rapid Prototyping technology, to manufacture the disposable pattern, and Investment Casting technology (lost wax casting).
The RP pattern is made by consecutive overlapping of layers, using Selective Laser Sintering technology. CastForm® is the material used for Rapid Casting patterns: born from the cooperation between DTM Corp. and CRP in 1996, it was developed for creating lost patterns in particular for highly reactive materials such as titanium. Production of ash during the evacuation of the ceramic shell has been reduced: the ash in fact, when in contact with the titanium, would produce chemical reactions (porosity) that would damage the casting, and have therefore to be eliminated before pouring the cast metal in the ceramic shell.

This technique allows complete freedom for shape conception: no more undercut and tool path problems during the CNC machining.
It’s therefore  possible to create the product along its mechanical stress directrixes, and to obtain a perfect reproduction of all details of the RP pattern, with tolerances and surface finishing like fully machined parts.

Rapid Casting procedure is composed of various steps, most important of them are:

• A disposable pattern in Castform is made through RP
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  The pattern undergoes wax infiltrations (immersion and capillarity) to increase its strength (to avoid handling breaks) and elimination  

Disposable pattern: laser sintering and red wax infiltration

• The pattern is immerged in a ceramic bath: 

• Slurries and stuccoing and exsiccation;
  
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  lost wax precision foundry (investment casting)
  

• The lost pattern is evacuated: Dewaxing with flash firing or in autoclave and drying of the ceramic shell
  

• Alloy casting with inductor or voltaic arc;

Titanium electrode in an arc furnace and revolving table and mold (a lightly different technique from the typical one for investment casting)

• pouring, cooling, reduction of the shell, shot peening, gate cutting, heat treatments  
  
  
  
  Example of disposable pattern, ceramic shell and casting
  
  
  
  
  
  
  
  The casting structure is formed of an aggregate of grains or polyhedral crystallites which produce isotropy compensation, while in a solid metal they are anisotropic: of course the isotropy generates great advantages, for example the FEM calculations are very close to the real behaviour thanks to the isotropy of the piece.

Micrography in which it's possible to see the alpha-beta structure in the grain center and the typical annealed alpha structure at the grain border.


In the beginning the classic cast alloys were tested, like aluminium ones , but almost immediately the two partners decided to make the big jump and study the

The Titanium alloys, already exploited in F1 with CNC machining or fabricated, had never been used in fact in casting processes with lost moulds in RP with complex and particular shapes like F1 particulars. It was therefore introduced in F1, as a world première, precisely by CRP Technology and Minardi F1 team in 1999, which made it possible to produce castings with complex geometrics and a high level of process reliability.
Among the positive properties of titanium there are:
Lightness (density 4,43 g/cm3), High specific Ultimate Tensile Strength (225,73 gMPa/cm3 per density unit) (UT S 1000 Mpa), low thermal and electrical conductivity, corrosion and stress corrosion resistance.
Titanium has 2 basis crystalline structures: one  (b) is body and face-centred cubic (over 883°C in CP), the other (a) is hexagonal close packed. The three alloys classes are therefore alpha, beta, alpha-beta. The additional elements can be alpha stabilizers (Al, O) or beta stabilizers (V, Mo).

The most used alloy is the Ti-6Al-4V (density 4.43 g/cm3).
This alloy is made up of 6% aluminium and 4% vanadium, and is an excellent combination of stress resistance and stiffness, with excellent wear resistance. 

• ductility, workability, dimensional and structural stability with annealing (Annealing is a quite generic term and indicates the process used to improve toughness, ductility at room temperature, dimensional and structural stability and, sometimes, Creep resistance.)
• or increase of UTS with a combined heat treatment Solution Treatment and Ageing: the STA

• Chemical milling, which removes the alpha case created when the metal comes into contact with the ceramic shell (only with titanium alloys);
• Hip, the application of hot isostatic pressure in an inert atmosphere (argon) used to eliminate porosity and micro-porosity from inside the material;
• TIG Weld repair in an inert atmosphere in order to remove porosity or hollows due to HIP;
• continuous X-ray inspection; 
• controlled shot peening for modifying the residual stress and inducing surface compression stress in order to increase fatigue resistance.

The final product is then worked by the CNC machines and undergoes a complete testing (material, RX, FPI, HT, etc…) ISO9001:2000 quality normative which therefore certifies the part.

Rapid Casting technology was immediately highly appreciated by customers because it provided significant advantages such as the possibility of best post-stress control of the piece compared to carbon laminated parts, durability and reliability of the detail (a casting is naturally isotropic for compensation), fewer design limitation and possibility to lightener (pockets) and get stiffer (adding ribs) the part during the racing season.  
Titanium Rapid Casting was later used also by other winning teams and it is still used a lot for several different parts of the F1 cars.

In 2002 this technology has been introduced into other motor series, in order to increase mechanical performance and reliability: ALMS, Rally Raid and MotoGP using Titanium Rapid Casting first, and, being Titanium banded in some series in 2003, Steel special alloys Rapid Casting later.

In 2002 Peugeot and MARCUS GRONHOLM won the World Rally Championship with Titanium uprights    and in 2005 Mitsubishi-Repsol Team won with LUC ALPHAND the Lisbon-Dakar Rally Raid with 17-4PH Steel uprights

The next year the Japanese manufacturer will try to re-confirm itself in the African Rally, always with this technology support.
“Hot” remarks from Mitsubishi staff (Thierry Viardot (TD) are: “First of all repeatability in production is great compared to previous weld fabricated uprights with a much better quality, no issue with rust (it’s an important problem for parts racing in desert and rain, hot and cold, mud and water, and so on… so very hard conditions!!), no cracks as usually noticed on the weld fabricated ones, very easy design and project for air intake (far more simple geometry due to "flexibility" of the casting model )”. In the meantime other teams in other series were able to bring F1 innovation on their racing cars.