MULTI-FUN will overcome certain restrictions and is aiming at 2 valuable strategic objectives in Metal Additive Manufacturing

Several Additive Manufacturing (AM) technologies have already proven their advantages for several applications applying different materials, from lot size 1 parts (e.g. injection moulding die with advantageous conformal cooling channels) over individualized series parts (e.g. hearing aids or medical implants adapted to each patient) to full series production with planned numbers >100.000, e.g. GE’s fuel nozzle for the “CFM LEAP” turbofan engine. The latter example is exploiting AM’s general principle “complexity for free” to a high degree by substituting a former assembly of 20 single metal parts into one, resulting in 25% less weight and ox higher durability.
The most widely used Metal AM (MAM) technology, Powder Bed Fusion (PBF), is not capable of applying other than single materials. Furthermore, the range of standard alloys is rather small, the costs for the machinery itself and the powder feedstock are comparably high. PBF is limited in size, too.

MULTI-FUN will overcome these restrictions and is aiming at 2 valuable strategic objectives in Metal Additive Manufacturing:

  • Provide a significant performance & efficiency gain in MAM products by fully INTEGRATED MULTI-FUNCTIONALITIES based on NOVEL ACTIVE MATERIALS
  • Enable MULTI-MATERIAL design in geometrically complex 3D metal parts WITHOUT SIZE LIMITATION by innovative, cost-effective AM technologies

MULTI-FUN is focussing on MAM applying combinations of min. 2 different materials in new generation of one-station AM equipment by combining directed energy deposition (DED) and metal spray technologies to maximize the benefits, specific material development will address bulk metals as well as embedded (“active”) material.
Large benefits are expected from incorporating nano-technologies due to outstanding material properties. Three of the several novel features are:

  • Integration of heat sink material with highest thermal conductivity (+50% to the state of the art, based on nanotechnology), resulting in up to 100% increase in local heat transfer rates
  • High degree of integral design e.g. insulated electrical conductors embedded in complex shaped metal structures (Figure showing a cut through demonstrator 3, the “see-through a-pillar”)
  • Adding sensing and data transfer capabilities into metal parts for condition and structural health monitoring purposes as well as process control techniques (Digital Twin)

Specific Objectives

S&T Objective 1:
Development of >5 new materials customized for AM, min. 3 of them using nanotechnology (KR1)

The use of nano-technology will be used to maximize thermal conductivity, minimize electrical conductivity and/or improve wear resistance of metals – always optimizing its compatibility to the metal bulk (demonstrators 1,2,5,6). Recent TRL4 developments of Aluminium alloys and low alloyed steel grades will be further developed for wire+arc additive manufacturing (WAAM) (demonstrators 2,3,4). Coating of optical fibres (OF) will be developed to maintain their sensing capabilities (demonstrators 2,5). In-situ alloying will provide further advanced materials solutions with high flexibility in compositions (demonstrators 2,6,7) and adjusted material properties.

S&T Objective 2:
Development of AM equipment and AM software - together being able to realize 10 different multi-material designs by min. 5 new technologies (KR1, KR2)

The development of AM hardware is driven by the need to combine different materials in distinguishable manner within a structure. It will produce requested material compositions during the layer build up - this in-situ alloying applies wire+wire or wire+powder feedstock by WAAM and metal spraying as new AM technique, i.e. atmospheric plasma powder deposition (APPD). Wire+OF will allow sensing capabilities, APPD will generate electrical conductive layers in between insulating layers in metal bodies. OF and Cu lines shall be able to transfer data. WAAM technologies have been selected as they have virtually no limitation on part’s size, lower raw material costs, minor efforts in precursor handling, lower hardware investment, easier implementation of multi-material combinations and top values of build-up rates. APPD technology enables to deposit metals into heat sensitive substrates avoiding thermal degradation and detrimental dilution between dissimilar metals. In total, at least 10 new material combinations applying. ≥5 new materials will be used by the 7 demonstrators for different applications. An advanced offline planning and process control tool is crucial for multi-material AM, with several processes working collaboratively and in parallel.

S&T Objective 3:
Manufacturing and evaluation of 7 physical demonstrators with multi-material design and integrated multi-functionalities (KR3)

KR1 (≥ 5 MATERIALS) and KR2 (≥ 5 TECHNOLOGIES) will be applied in 10 different combinations in 7 demonstrators, belonging to 3 use cases (structural parts, moulds, test equipment), addressing 4 different markets (automotive, aviation, space and production industry), each of them taking advantage of the high built-up rate of WAAM for the metal bulk and specialized AM processes for the integration of active materials. Lessons learnt workshops will accelerate the build-up of a common knowhow pool, creating novel skills for multi-material & multi-functional design.

S&T Objective 4:
Supervising the significant reduction of environmental and economic impact by LCA (KR1, KR2, KR3, KR4)

All MULTI-FUN developments concerning AM materials, hardware, process strategy and demonstrator design and manufacturing will be continuously supervised through feedback loops improved. LCA, LCC, safety and Eco-efficiency will ensure the >40% rise in efficiency, quality and reliability as well as the reduction of resources and cost >35%. Table 10 (page 23) shows the overfulfilment of these topic requirements on KPIs.


KR1 – Advanced Metallic Materials:
Advanced structural metals & corresponding active material solutions for innovative multiple functionalities


KR2 – Novel AM equipment:
Hard-& software for multi-material processing & in-situ alloying, toolpath planning & process control for several AM technologies working in parallel


KR3 – Multi-Material Design-Knowledge:
New knowledge on increased efficiency of parts & moulds due to integrated, multi-material-based functions


KR4 – Standardisation knowledge:
Enhanced knowledge to contribute to standards and support regulatory bodies adapting to multi-material AM