Green manufacturing: Creating high strength metal matrix structures (HYBRIDSURF)

Research Project, 2019

Purpose and goal: HYBRIDSURF intended to evaluate the potential of introducing a totally new approach for hard turning, where the inherit disadvantages like i) control of (minimizing) dimensional errors, ii) industry acceptance of surface and subsurface microstructure alterations surfaces with white layers on functional surfaces, iii) control of (or minimizing) surface tensile residual stresses were turned into advantages. The aim is to use improved cooling strategies with modified cutting edges and process settings to create an ultra-high strength surface on the top layer while machining.

Expected results and effects: HYBRIDSURF showed the potential in creating the intended surface modification (surface thickness, occurrence, etc), however, given the inferior cooling we were not successful in producing the desired type of surface modification as planned at higher cutting speeds, e.g. higher productivity. This shows the need of superior cooling while hard turning to suppress the cutting temperatures and thereof being successful in producing a superior surface quality at higher cutting speeds, which is also considered to have a strong positive impact on the strength of the as-produced parts.

Approach and implementation: The project was started via a state-of-the-art literature search on what is happening in the area and what is the latest. A DoE was then compiled, which included both simulations and experiments. Where simulations were used as a guide to understand how to minimize our experiments. Subsequently, a number of different experiments were carried out, which in turn were characterized via LOM, SEM and XRD and then feedback the collected data against the simulations. Analysis and characterization were performed at RISE and Chalmers and the tests were conducted at Chalmers.