Materials

SteelCast IronAluminiumMagnesium

Scheme Iron based materials: Steels

 

According to DIN EN 10020:2000-07 steels are materials with an iron content higher than any other alloying element and with C-contents <2.06 wt.%. Steels with C-contents between 0.25 and 1 wt.% exhibit excellent surface hardenability. High alloy steels are remelted for refining the carbides.

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Subheading steels: EB Hardening

Picture Steels: EB-Hardening ©ebeam

  • Depth: 0.2 … 1.5 mm
  • Pre-conditions: hardenable steel, C-content: >0.3…0.7, hardened and tempered state (homogeneous carbon distribution), sufficient wall thickness for realising self quenching
  • Aims: martensitic transformation, increase in hardness (2-4-fold; 600-800HV0.3), generation of internal compressive stresses beneath the surface, high precision in contour uniformity, improvement of wear resistance and fatigue strength, increased load support for subsequent thin film treatments (e.g. nitriding, PVD, CVD, boriding)
  • Own results: Q+T steels, unalloyed and alloyed tool steels

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Subheading steels: EB Remelting

Picture Steels: EB-Remelting ©ebeam

  • Depth: 0.2 … 9 mm
  • Aims: elimination and refinement of segregations and microstructural inhomogeneities (e.g. sulfide inclusions), increase of hardness (up to ?fold; ?HV0.1), improvement of the wear resistance and fatigue strength
  • Own results: Q+T steels, high alloy steels


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Subheading steels: EB Alloying

Picture Steels: EB-Alloying ©ebeam

  • Depth: 0.5 – 1.5 mm
  • Additives: Fe- (FeCrC, FeB, FeCrV), Ni-, Co-base (two step additive deposition)
  • Aims: increase of hardness (up to 2-3fold; 800-1000HV0.1) by e.g. carbide precipitations (FeCrC additive), improvement of the wear and corrosion resistance (better than after nitriding)
  • Own results: 30CrMoV9, 38CrMoV21-14

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Subheading steels: EB Cladding

Picture Steels: EB-Cladding ©ebeam

  • Depth: 0.5 – 2 mm
  • Additives: Fe-, Ni-, Co-base (single-step additive deposition)
  • Aimes: formation of thermal stable layers, increase in hardness (600HV0.3), improvement of the wear and corrosion resistance
  • Own results: austenitic steels

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Subheading steels: EB Welding

Picture Steels: EB-Welding ©ebeam

  • Depth: 0.5 – 50 mm (at UA = 80 kV)
  • Additives: none (but possible)
  • Pre-conditions: weldability (cf. carbon equivalent)
  • Aims: use of deep welding effect, narrow seams, small heat affected zone, minimization of the hardening effect (< 450HV0.5), crack and pore free, increased weldability by means of multi-spot welding
  • Own results: similar and dissimilar joints (steel/steel, cast iron/steel, etc.)

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Subheading steels: EB Ablating

Picture Steels: EB-Ablating ©ebeam

  • Depth: 50 – 100 µm (engraving); > 100 µm (profiling)
  • Additives: none
  • Aims: generation of functional surfaces by means of applied patterns and engravings, e.g. lubrication reservoir, for improvement of the adhesion of thermal sprayed coatings, generation of grey scale images for identification
  • Own results: Q+T and tool steels, austenitic steels with brushed surface

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Scheme Iron based materials: Cast iron

Cast iron is an iron-carbon alloy with both high Si- and C-content (>2.06 wt.%) and is characterised by its good castability. Solidification under equilibrium conditions (stable Fe-C systeme) leads to steel like matrix microstructure (pearlite, ferrite or austenite) with graphite (lamellar, globular, vermicular). In case of pearlitic and pearlitic/ferritic matrix, the cast iron is hardenable analogeous to steels. Using EB remelting, the solidification occures after meta stable system (ledeburit) and a hard, wear resistant surface is formed.

 

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Subheading cast iron: EB Hardening

Picture Cast iron: EB-Hardening ©ebeam

  • Depth: 0.2 … 1.5 mm
  • Pre-conditions: hardenable matrix microstructure (pearlite), hardened and tempered state (homogenous carbon distribution), sufficient wall thickness for realising selfquenching
  • Aims: martensitic transformation, increase in hardness (2-4-fold; 600-700HV0.3), generation internal compressive stresses in the surface, high precision in contour uniformity, improvement of wear and fatigue strength with graphite lubrication
  • Own results: cast steel, pearlitic/ferritic cast iron

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Subheading cast iron: EB Remelting

Picture Cast iron: EB-Remelting ©ebeam

  • Depth: 0.3 …2 mm
  • Aims: elimination of the graphite, metastable solidification, generation of an ledeburitic microstructure, crack-free layers due to pre-heating (approx. 450 °C), elimination of casting defects, refinement of the microstructure, increase of hardness (600-700HV0.3), improvement of the wear resistance and fatigue strength
  • Own results: grey cast iron, malleable cast iron

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Subheading cast iron: EB Alloying

Picture Cast iron: EB-Alloying ©ebeam

  • Depth: 0.5 – 2 mm
  • Additives: Ni-, Co-base (two step additive deposition)
  • Aims: formation of intermetallic phases, increase of hardness (up to 3fold; 400-600HV0.1), improvement of the wear and/or corrosion resistance
  • Own results: grey cast iron

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Subheading cast iron: EB Cladding

Picture Cast iron: EB-Cladding ©ebeam

  • Depth: 0.5 – 4 mm
  • Additives: Fe-, Ni-, Cr-, Co-base (single-step additive deposition)
  • Aims: increase of hardness (400-600HV0.3), improvement of the wear and/or corrosion resistance, repair welding, regeneration
  • Own results: GJL, GJS, GJV

 

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Subheading cast iron: EB Welding

Picture Cast iron: EB-Welding ©ebeam

  • Depth: 0.5 – 10 (40) mm (at UA = 80 kV)
  • Additive: without or with Ni-base (single-step additive deposition)
  • Aims: improvement of the weldability by means of optimized beam deflection and the use of additive, narrow seams, use of keyhole welding, narrow heat affected zone, minimization of the hardening effect (< 450HV0.5), crack and pore free
  • Own results: similar and dissimilar joints (cast iron/cast iron, cast iron/steel, etc.)

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Subheading cast iron: Process combination

Picture Cast iron: Process Combination ©ebeam

  • Combinations: EBR/EBA + nitriding (N), + PVD/CVD hard coating
  • Motivation: typical high C- and Si-content and the graphite in cast irons compromise the nitriding and coating behaviour, thin coatings deposited on soft graphite break through under loading (no load support)
  • Properties: simultaneous improvement of the wear and corrosion behaviour

 

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Scheme aluminium materials

Opposite to the iron base alloys, liquid phase surface treatments are exclusivly used for Al alloys due to the absence of allotropic transformations in the solid state.

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Subheading aluminium: EB Remelting

Picture Aluminum: EB-Remelting ©ebeam

  • Depth: 0.5 … 9 mm
  • Aims: increase in hardness (up to 2fold; 120-180HV0.1), elimination of casting defects, microstructure refinement (e.g. AlSi10Mg: SDAS: 3 … 6 µm)
  • Own results: AlSi cast alloys, spray-formed Al alloys DISPAL Sxx

 

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Subheading aluminium: EB Alloying

Picture Aluminium: EB-Alloying ©ebeam

  • Depth: 0.5 … 1.5 mm
  • Additives: Cu-, Ni-, Co-, (Fe)-base (single or two step addive deposition)
  • Aims: microstructure refinement, formation of metastable, intermetallic phases, increase in hardness (up to 2-4fold; 250-450HV0.1), improvement of the wear, corrosion and/or thermal resistance, improved load capacity for subsequent surface treatment generating thin coatings (e.g. plasma nitriding, PVD)
  • Own results: Al cast and wrought alloys, DISPAL Sxx

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Subheading aluminium: EB Dispersionalloying

Picture Aluminium: EB-Dispersionalloying ©ebeam

  • Depth: 0.5 … 1.0 mm
  • Additives: (Cu-, Ni-, Co-base) + WSC, B4C, Al2O3 (single or two step addive deposition)
  • Aims: generation of surface composite alloy, formation of metastable, intermetallic phases, increase in hardness within the surface matrix microstructure with improved load support (up to 2-4fold; 250-450HV0.1), local high hardness resulting from dispersions (1500-3000HV0.05), improved wear resistance (10fold)
  • Own results: AlSi cast alloys

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Subheading aluminium: EB Cladding

Grafik Aluminium: EB-Auftragen ©ebeam

  • Depth: 0.5 … 4.0 mm
  • Additives: Al-, Cu-, Ni-, Co-base (single step additive deposition)
  • Aims: formation of metastable, intermetallic phases, increase in hardness (up to 2-4fold; 250-450HV0.1), improvement of the wear, corrosion and/or thermal resistance
  • Own results: Al cast and wrought alloys

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Subheading aluminium: EB Welding

Picture Aluminium: EB-Welding ©ebeam

  • Depth: 0.3 … 100 mm (at UA = 80 kV)
  • Additive: none (but possible)
  • Conditions: weldability of the material used, precise gap-preparation (tight tolerance gap), cleaning
  • Aims: narrow, deep seams, without cracks and pores
  • Own results: Al cast alloys, Al wrought alloys and spray-formed Al alloys (with pre-heating)

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Subheading aluminium: EB Ablating

Picture Aluminium: EB-Ablating ©ebeam

  • Depth: 50… 200 µm
  • Additive: none
  • Aims: generation of dimples and profiles with different cross sections, e.g. for improved interlocking between liner and casting
  • Own results: Al cast and wrought alloys

 

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Scheme magnesium materials

 

Analogous to Al alloys, Magnesium alloys exhibited no allotropic transformation in the solid state. Therefor, liquid phase surface treatments are suitable for Mg alloys. This results in an increased corrosion resistance as well as enhanced hardness and wear resistance. Al based additives are suitable for EB alloying. Fe, Ni, Cu or Co containing additives had a significantly higher potential for hardness increase, but have a negative effect on the corrosion behaviour.

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Subheading magnesium: EB Remelting

Picture Magnesium: EB-Remelting ©ebeam

  • Depth: 0.3…2 mm
  • Aims: Improvement of the corrosion resistance by microstructur refinement and generation of a supersaturated solid solution
  • Own results: Mg cast and wrought alloys

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Subheading magnesium: EB Alloying

Picture Magnesium: EB-Alloying ©ebeam

  • Depth: 0.3 ... 2 mm
  • Additives: Al99, AlSi12, AlSi30 (single-step additive deposition, limited choice of additive due to deterioration of the corrosion resistance)
  • Aimes: microstructure refinement, dissolution and new precipitation of intermetallic phases, increase of hardness (up to 3-fold; 150-300HV0.1), improvement of the corrosion resistance by increased Al content in the surface layer
  • Own results: Mg cast alloys (AZ31, AZ91)

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Subheading magnesium: EB Dispersionalloying

Picture Magnesium: EB-Dispersionalloying ©ebeam

  • Depth: 0.5 – 2 mm
  • Additives: Al-base (see EBA) + SiC, TiC, B4C, Al2O3 (single-step additive deposition)
  • Aims: improvement of the corrosion resistance by increased Al content in the surface layer and microstructure refinement, formation of intermetallic phases, increase of hardness of the layer matrix (up to 3-fold; 150-300HV0.1) and dispersed hard carbides (800-2000HV), improvement of the wear resistance
  • Own results: Mg cast alloys (AZ31, AZ91)

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Subheading magnesium: EB Cladding

Picture Magnesium: EB-Cladding ©ebeam

  • Depth: 0.5 – 2 mm
  • Additives: Al-base (single-step additive deposition)
  • Aims: significantly higher Al contents in the surface than for EBA, markedly improved corrosion resistance, hardness increase (150-250HV0.1), (improvement of strength and wear resistance)
  • Own results: Mg cast alloys

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Subheading magnesium: EB Welding

Grafik Magnesium: EB-Schweißen ©ebeam

  • Depth: 0.5 – 35 mm (at UA = 80 kV)
  • Additives: none
  • Aims: use of deep welding effect, narrow seams, narrow heat affected zone, minimal influence of the base materials strength, crack and pore free (also for squeeze casting alloys)
  • Own results: AZ91, AZ31B+C, AZ61A, AZ80A, AM50

 

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