Co-funded by the National Operational Programme 'Enterprise and Competitiveness' 2014-2020 ERDF of the Italian Ministry of Economic Development (now the Italian Ministry of Enterprise and Made in Italy), the project follows the lines of development on the production of helical gears. The qualitative and quantitative objectives were fully met, with potential applications in the automotive sector useful for increasing the reliability of high-performance components, reducing the use of energy and resources compared to traditional technologies.
The development of innovative technologies for the manufacturing of complex gears is at the heart of the strategy of SACMI's Advanced Materials BU, which has finalised the CPM project (Development and realisation of a process for the production of complex gears by compacting metal powders) under the co-financing of the Italian Ministry of Enterprise and Made in Italy and with its partner Officine Meccaniche Pontillo.
Concluded in January, the proposed 36-month project aimed to bring further innovation to the powder metallurgy process, which optimises material and energy consumption with respect to traditional metallurgy.
The intrinsic advantages of the sintering process - which also include greater durability of the moulds and uniformity of the finished part - are the prerequisite for the activity, which aimed to reduce the current gap in terms of the mechanical characteristics of components made using the casting or plastic deformation technique.
The first step of the project was the realisation of prototypes from the 3D model data, which was useful to start operating tests of the system for powder compaction and surface densification. This first phase included the search for the most suitable geometry for the application, realised by means of a direct metal laser sintering (melting) process (DMLS).
In practice, with this technique, the article is compounded by sintering successive layers (additive manufacturing) until the model is complete, then brushed - to eliminate residual powder - and heat-treated in special kilns. Tests were then carried out on different types of materials (steel, titanium, aluminium alloys, etc.) to identify the most suitable one for the proposed application.
The project was finalised following the guidelines of the circular economy, starting with the complete recycling of the materials used for the samples. The main target of the proposal is the automotive sector to propose a viable - superior mechanical properties of the gear - and cost-effective alternative to the traditional techniques in use (forging, casting and machining) for the production of high-performance components.
These types of gears are found in various parts of the vehicle, e.g. the gearbox. Through this innovative technology, the aim of the project was to produce components with optimal density (99 per cent of the theoretical density), without defects in the microstructure and with dimensional, geometric and microgeometric gear characteristics suitable for operation.
Great satisfaction was expressed by the teams of the two companies for the full achievement of both the quantitative and qualitative targets. Around 50,000 components were produced on a 2,000 kN press with an innovative mould wall lubrication system, with optimum densification close to 7.6 g/cm3. These results demonstrate significant technological advancement, forming the basis for the development of the application at industrial level.
The CPM project follows a previous line of development of Helical Gears, then industrialised by SACMI in specific applications already acknowledged by the market for the innovative features of the proposed process. Co-financed by the Italian Ministry of Enterprise and Made in Italy, this project was also finalised by SACMI together with its partner Officine Meccaniche Pontillo, an ISO 14001-certified Green Company, confirming an important synergy in terms of skills, know-how and structures.