Real Components Coated

Within the remit of WP7 three real components have been coated with the newly developed HardAlt coatings. The three components are a rod for a shock absorber, drill bit and piston arm. The coated components are shown below. At present tests are being conducted to investigate how these components perform in their respective working environments.

Plating Methods

Within WP2 and WP3 pure Ni-P and composite Ni-P coatings reinforced by SiC nanoparticles and MWCNTs were produced applying direct current (DC) electrodeposition technique. The effect of the electrodeposition parameters such as the applied current density, bath composition, bath pH and reinforcing particle content on the microstructural characteristics of the composite coatings has been investigated. The optimum electrolysis conditions based on the enhanced mechanical and tribological character of Ni-P nano-composite electro-coatings have been determined.

Characterisation Results

Structural, mechanical and tribological characterisation of Ni-P based coatings is in progress. The first set of coatings, pure Ni-P and Ni-P doped with SiC nanoparticles or carbon nanotubes, has been completely evaluated and data provided to all partners. Based on the results, the second set of coatings was prepared: identical coatings but post-annealed at different temperatures. This second set has undergone mechanical and tribological testing; special attention was paid to tribological mechanism and the effect of annealing temperature on structure and mechanical properties, namely hardness and elastic modulus. Again, the results have been used by project partners to further optimize deposition process and prepare third coating series, which is being tested. It is obvious now that optimum combination of post-treatment (annealing) and dopant can lead to excellent functional properties, which clearly outperform present Ni-P coatings.

Key Highlights

  • Functional Ni–P matrix composite coatings can be produced from nickel sulphate and nickel sulphamate based baths with the addition of the proper combination of organic additives. Depending on the applied conditions and combinations of organic additives, a wide range of Ni–P/SiC and Ni-P/CNT coatings with P content in the range of 3–19 wt% have been produced

 

  • The incorporation rates of reinforcing nano-particles in DC coatings are low, up to 2 wt%. No serious problems regarding particle agglomeration (of any type) was detected.

 

  • The deposition efficiency is about 30–75% depending on bath chemistry, bath pH and deposition current.

 

  • XRD data demonstrates that coatings exhibit amorphous to nanocrystalline structures. By altering the bath composition it was possible to transform the structure of the coatings from the completely amorphous phase to nano-crystalline with the presence of either Ni or Ni12P5 and Ni8P3 phases. The morphology of the coatings also correlates to the electrolysis conditions. Thus, at low current density spherical formations and pyramidal or polyhedron crystallites are present, whilst at higher current densities smooth and fine coatings surfaces are produced.

 

  • The roughness of the different type of electrodeposits produced within WP3 increases as current density of the plating decreases.

 

  • Despite the low number of reinforcing nanoparticles particles in the alloy matrix produced by DC, the micro-hardness of the Ni-P composite electrocoatings have been improved. Pure Ni–P coatings exhibited hardness values in the range of 550 to 650 HV depending on their structure. The addition of SiC nanoparticles or MWCNT has resulted in an increase in the micro-hardness of up to 800 HV. The hardness of these alloys further increases up to 1350 HV after appropriate heat treatment due to the precipitation of the hard Ni3P phase.


  • The adhesion tests demonstrated that the presence of the reinforcing nanoparticles in the Ni-P matrix does not significantly alter the quality of the composites compared to those without added particles.

 

  • All tested coatings showed excellent/very good tribological properties. The wear data showed that the presence of the reinforcing nanoparticles increased the wear resistance of the composite coatings compared to the pure Ni-P. The wear mechanisms detected in corresponding tracks revealed the presence of abrasion and oxidation in composites.

 

  • Post heat treatment improved both the frictional behaviour and wear resistance of Ni-P and Ni-P/SiC electrodeposits but degraded both the frictional behaviour and wear resistance of the Ni-P/CNT electrodeposits.

 

  • Ni-P composite coatings have better frictional and wear properties than hard chrome coatings.

 

  • Ni-P composite coatings are comparable to some of the most advanced materials in the market.

 

  • It is promising that even composites in which low incorporation rates of nano particles (up to 2 wt%) within the Ni-P matrix are observed, exhibit enhanced mechanical properties compared to that of the pure Ni-P. Therefore, it is expected that properties will be improved in the case of pulse-plated composites as higher nanoparticle codeposition rates can be achieved and the reinforcing particles more uniformly distributed within the alloy matrix.

 

  • WP5 experiments regarding pulse plating of composite coatings are in progress.
The HardAlt project received funding from the European Community’s Seventh Framework Programme managed by REA – Research Executive Agency, under grant agreement No: 606110. Funding scheme: SME-2013-2: Research for SME Associations
The HardAlt project received funding from the European Community’s Seventh Framework Programme managed by REA – Research Executive Agency, under grant agreement No: 606110. Funding scheme: SME-2013-2: Research for SME Associations

Latest News

HardAlt video available click here.

 

HardAlt: Real components coated with newly developed HardAlt coatings. For work progress click here.

 

June 2016 HardAlt members participate in European Commission Workshop to discuss REACH regulations. Click link for more information.

 

August 2016 HardAlt member has meeting with Rolls Royce Aerospace Engines to discuss future coatings.

 

HardAlt objectives presented at European Parliamentary Meeting. Click here to read more.

 


Events

HardAlt final review meeting held on 26th January 2017 in Brussels. Click here for the Agenda and Minutes.