The origin
Tailored Blanks today
Reduction of CO

emissions
Tailored safety
Lower production costs with improved quality
Additional benefits
Cost comparison Tailored Blank/conventional concept

Modern automotive engineering is in a continuous growing conflict: on one hand there are the requirements of the new car models to have a higher engine power, more comfort and a plus of safety. And on the other hand there is the claim for a better environmental impact – that means lower fuel consumption, decreasing emission values and an improved recycling capability.

Having this background in mind the importance of intelligent lightweight construction has to be seen in new importance, because not only the specific for material properties are used to full capacity, e.g. the modern high strength and extreme strength types of steel, but also the benefits of the new method of construction and the innovative manufacturing technologies are used optimal as well. A contribution to the realisation of intelligent lightweight construction within a Body in White as the biggest cohesive assembly is the application of Tailored Blanks - prefab semi-finished products of steel.

“Tailored“ means on one hand the construction of the blanks, which are already stamped to required size, joined with blunt stack and welded by a laser beam without any overlapping by the Tailored Blank supplier. Afterwards they can be formed in the press shop of the OEM´s. On the other hand, “tailored” means that all characteristics and features of the blanks are adaptable exactly to the later requirements of the components.


Fig. 1: elementary requirements in automotive engineering

TOP

The Origin
Tailored Blanks were used for series production for the first time in 1985 when a large sized blank was needed for a floor panel implementation, which could not be rolled because of the required size. The solution of this problem was the intention to piece the blank together connecting two single sheets in blunt stack with the same properties by using the then new technology of laser-beam welding.
TOP

Tailored Blanks Today
Since then Tailored Blanks became a versatile and high flexible primary product of Body in White. Today the tailored and laser welded blanks are made up of two up to seven individual sheets of different thickness, characteristics, strength and surface coating. The run of the weld seam can at this be executed linear or not linear.

Fig. 2: schematic configuration of a blank for a front door inner

TOP

Reduction of CO2 emissions
Due to the combination of diversified individual sheets it is possible to customise the strength and the rigidity specifically on the local requirements of the final sub-assembly. The result is in a part a considerable weight reduction in comparison to conventional applications, which affect positively not least the fuel consumption and the CO2 emissions of the whole vehicle.
TOP

Tailored safety
By implicating Tailored Blanks the crash performance of a car can be influenced positively. The realisation of a front longitudinal rail as a Tailored Blank e.g. and the usual arrangement of the thinner and more flexible material in the front of the vehicle will relieve the released energy in case of a front crash for the most part in the source of the deformation. The thicker executed front rail areas provide the protection of the passengers’ cabin.
TOP

Lower production costs with improved Quality
Due to the application of Tailored Blanks you can furthermore normally avoid the use of additional reinforcement plates in highly stressed areas, which implicates additional weight benefits and a reduction of diversity in partpieces and leads therewith to a decrement of production and logistic costs. The lower number of single components leads moreover to a reduction of the component tolerance of the respective sub-assembly.
TOP

Additional Benefits
Additional benefits of Tailored Blanks are first of all within the utilisation of the laser welding as a modern joining technique. Laser welded connexions have a significant better rigidity in comparison to spot-welded connexions as well as a distinctly upper compound rigidity due to the solid run of the laser weld.

In case of a crash the solid run of the laser seem leads to a more uniform transmission of force into the Body in White structure. Due to the fact, that the partpieces will be joined in blunt stack there are no overlappings (flanges) like there are known by assembling several components by spot welding technique. This opens up new constructive solutions/ scope for the development design /constructive engineer.

Due to the density of laser welded connexions there is almost no need of sealing the connexions anymore which leads to a secondary weight reduction also to a minimisation of production and material costs as well as an improved corrosion protection.
TOP

Tailored Blank or conventional Solution - Cost Comparison
There are many factors that will become important with the complex question, if it is recommendable to integrate a Tailored Blank into Body in White conception and production instead of a conventional solution.

excerpt is a programme which permits an overall cost calculation for integrating Tailored Blanks in comparison to a conventional solution reflecting your individual productions settings. Quick, easy and comfortable!
TOP