Friction stir based welding and processing technologies - processes, parameters, microstructures and applications: A review

Friction surfacing—A review

Characterization of austenitic stainless steel friction surfaced deposit over low carbon steel

Tool steel H13 was friction surfaced on low carbon steel substrates. Mechtrode (consumable rod) rotational speed and substrate traverse speed were varied, keeping the axial force constant. The effects of process parameters on coating characteristics and integrity were evaluated. A process parameter window was developed for satisfactory deposition of tool steel coatings. Coating microstructures were examined using optical microscopy, scanning electron microscopy, and transmission electron microscopy. Microhardness tests, shear tests, and bend tests were conducted on coatings. The results show that coating width is a strong function of mechtrode rotational speed, while coating thickness is mainly dependent on substrate traverse speed. Lower mechtrode rotational speeds results in wider coatings, while higher substrate traverse speeds produce thinner coatings. Thinner coatings exhibit higher bond strength than thicker coatings. Coatings show no carbide particles, yet exhibit excellent hardness (above 600 HV) in as-deposited condition due to their martensitic microstructure.

Friction surfaced tool steel (H13) coatings on low carbon steel: A study on the effects of process parameters on coating characteristics and integrity

https://research.aalto.fi/files/11746358/1_s2.0_S2212827113002655_main.pdf

Influence of process parameters in the friction surfacing of AA 6082-T6 over AA 2024-T3

This paper discusses the procedures for data collection, management and optimisation of the friction surfacing process. Experimental set-up and characteristics of measuring equipment are found to match the requirements for accurate and unbiased data signals. The main friction surfacing parameters are identified and the first stage of the optimisation process is achieved by visually assessing the coatings and introducing the substrate speed vs. force map. The optimum values from this first stage forms a region around the middle of a trapezium-shaped area whose borders are found experimentally. Data collected for the second stage were analysed using the least squares method which were applied to find the coefficients of a second order regression model. Advantages of applying artificial intelligence methods to friction surfacing modelling are also described and the higher accuracy achieved using neural networks demonstrated.

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An integrated approach to friction surfacing process optimisation

Friction surfacing/coating provides a valuable mechanism for the repair of steam turbine blades, which can have a very high replacement cost. Optimum process conditions are essential and this paper details a finite element model based analysis that takes into account the dynamics of temperature gradients due to complex geometry. The model can determine appropriate values for traverse speeds required to produce an optimum interface bonding temperature. The research will lead to the inclusion of the process model in a realtime control system.

Modelling of the Friction Surfacing Process for Turbine Blade Reclamation

Friction surfacing is an advanced manufacturing process that has been successfully developed and commercialised over the past decade. This paper considers a novel approach that will allow the expansion of the range of potential applications in the area of turbine blade repairs and manufacture including manufacture of bladed components, aerofoil replacement repairs, blade tip extensions, surface build up (including erosion/corrosion damage) and shoulder wear. The process is modeled using two types of model — Controlled AutoRegressive Integrated Moving Average (CARIMA) for the dynamics and neuroruzzy relationships for the static. Self tuning extremum control integrates both models and produces optimal control in real time. The algorithm is shown to follow successfully a predefined setup pattern.

B. Jaworski

Papers

An integrated approach to friction surfacing process optimisation

Modelling of the Friction Surfacing Process for Turbine Blade Reclamation

Modelling, Optimization and Control Integration of the Friction Surfacing Process