Critical Analysis of the Current Trends in Ensuring the Holes Quality when Drilling CFRP/Titanium Alloy Stacks
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Abstract
In recent decades, CFRP/titanium alloy stacks have become widespread in the production of aircraft components, as opposed to the use of separate FRP and metal alloys, which is due to the higher physical-mechanical and operational properties of the stacks compared to alloys. Along with the expansion of the scope of application of CFRP/titanium alloy stacks, the gross share of mechanical operations also increased, which is largely related to the need to connect CFRP layers with the layers of titanium or aluminum alloy. In this context, the most common machining operation is drilling holes. The simultaneous machining of stacks with different structures, chemical composition, and physic-mechanical properties raises a number of challenges for both researchers and engineers in terms of ensuring the economic accuracy and quality of the machining at the same time in the layers of CFRP and titanium alloy. Despite the large amount of research devoted to the drilling of CFRP /titanium alloy stacks, a comprehensive understanding of the basic parameters of drilling and their influence on the accuracy and quality of holes is insufficient.
This paper aims to provide a critical review of drilling mechanisms and their impact on machining parameters in the fabrication of holes in CFRP/titanium alloy stacks for the research and manufacturing communities. In this regard, a comprehensive analysis of the literature was conducted to summarize the current achievements in the field of stack machining. Aspects considered include the influence of cutting parameters and machining technologies, hole quality parameters. Particular attention was paid to the discussion of various parameters of drilling at the interface of the layers of the package, as well as the influence of different strategies and sequences of drilling on the results of drilling CFRP/titanium alloy stacks. In addition, current research shortcomings and future research trends are indicated. The review aims to provide the scientific and industrial community with a comprehensive understanding of stacks drilling mechanisms.
