A comparative study on machining and tool performance in friction drilling of difficult-to-machine materials AISI304, Ti-6Al-4V, Inconel718

Friction drilling is a widely used process to produce bushings in sheet materials, which are processed further by thread forming to create a connection port. Previous studies focused on the process parameters and did not pay detailed attention to the material flow of the bushing. In order to describe the material behaviour during a friction drilling process realistically, a detailed material characterisation was carried out. Temperature, strain rate, and rolling direction dependent tensile tests were performed. The results were used to parametrise the Johnson–Cook hardening and failure model. With the material data, numerical models of the friction drilling were created using the finite element method in 3D as well as 2D, and the finite volume method in 3D. Furthermore, friction drilling tests were carried out and analysed. The experimental results were compared with the numerical findings to evaluate which modelling method could describe the friction drilling process best. Highest imaging quality to reality was shown by the finite volume method in comparison to the experiments regarding the material flow and the geometry of the bushing.

Finite Element and Finite Volume Modelling of Friction Drilling HSLA Steel under Experimental Comparison.

Friction drilling is one of the most promising methods for hole making in thin sheets of conventional structural alloy materials (aluminum, steel, copper, titanium, etc.) and novel polymer composites. Despite almost a hundred year history of studying friction drilling, it is still highly relevant and is actively developed. The aim of the present review is to cover as fully as possible all aspects of this technology. The paper analyzes the advantages and disadvantages of friction drilling, discusses the influence of technological parameters on the drilled hole quality. The technological parameters considered are not only the feed rate and spindle speed, but also the tool configuration. The quality of the holes refers to their strength, inner surface hardness, hole geometry and roughness, bushing geometry, and so on; therefore, they are also analyzed. From a fundamental point of view, frictional drilling is interesting in that it causes structural changes in the material as a result of severe plastic deformation, which is discussed in a separate section. Approaches for the process modeling are considered which quite accurately predict the material behavior. A technically more advanced technology of a new generation is discussed, namely flow drill screwdriving. A general conclusion is that despite the widespread use of friction drilling, including by well-known engineering companies, the technology continues to develop with regard to the changing needs of the industry and the market and strengthens its position in the industry.

Friction drilling: a review

Friction drilling of AA7075-T6 and AZ31B alloys under dry and oil containing ceramic particulates

Thermal friction drilling is a non-conventional hole making process, which uses a rotating tool to penetrate the workpiece and create a bushing. Friction drilling of brittle cast alloys is likely to result in severe petal forming and radial fracturing. This research investigates the effect of pre-drilling diameter and depth on the produced bushing cracks and petal formations while drilling cast aluminum alloy (A380). A three-dimensional finite element model of high-temperature deformation and large plastic strain is performed by using ABAQUS software. Modeling by using dynamic, temperature-displacement, explicit, as well as the adaptive meshing, element deletion, interior contact, and mass scaling techniques, is necessary to enable the convergence of the solution. The finite element analysis results predict that the pre-drilling has a significant effect on the produced bushing shape. The effect of initial deformation decreases with pre-drilling, leading to fewer cracks and petal formations. Hence, the obtained bushing length increases, so providing a more load-bearing surface that leads to a stiffer joint. Additionally, the effect of pre-drilling on the produced temperature is studied, and the results reveal that by increasing the pre-drilling diameter or depth the temperature decreases. Therefore, less workpiece material melting occurs, which leads to less adhering on the tool surface, so fewer cracks and petal formations.

https://jacm.scu.ac.ir/article_15729_a1dff6ffb2ec11f9f1b93377c222ec3d.pdf

Pre-drilling Effect on Thermal Friction Drilling of Cast Aluminum Alloy Using Thermo-mechanical Finite Element Analysis

A thermo-mechanical finite element simulation model to analyze bushing formation and drilling tool for friction drilling of difficult-to-machine materials

Ehsan Souri

Papers

A thermo-mechanical finite element simulation model to analyze bushing formation and drilling tool for friction drilling of difficult-to-machine materials