Links Between Machining Parameters and Surface Integrity in Drilling Ni-Superalloy

In aerospace industry, the manufacturing of critical parts (high energy components) requires an important validation process to guarantee the quality of the produced parts, and thus their fatigue lifecycle. Globally, this validation consists in freezing the cutting conditions using metallurgical analysis or fatigue trials, and a test on the first article. This process is extremely complex and expensive. In this way establishing the correlation between the cutting conditions and the surface integrity will help us to optimize the manufacture of those parts. In this article, by the means of an experimental method, we define a domain of validation by combining the cutting conditions according to the classic criteria established by AFNOR E66-520 norm (Couple-Tool-Material) and the criteria of surface integrity for the drilling of a Nickel-base superalloy. The experimental device consists in drilling a Ø15.5 mm hole on a 3-axis milling centre instrumented by a 4 components Kistler dynamometer (Fx, Fy, Fz and Mz), a spindle power sensor “Watt-pilote” and three accelerometers placed following the directions X, Y and Z. Scanning Electron Microscopy (SEM) observations, micro-hardness tests and topographic measurements with an optical profilometer, are carried out to characterize the metallurgical state of the holes manufactured. Finally, correlations were respectively made between the cutting conditions, the recorded signals and the metallurgical state of the holes

Identification of influent factors on surface integrity in nickel-base superalloy drilling

For the critical rotating components in aeronautical industry, the metallurgical quality achieved after machining conditions could determine their mechanical behaviour in fatigue. To guarantee this quality, the tools, materials and cutting conditions are frozen during the validation process by a cutup part following by an acceptable surface integrity. Even with the fixed parameters, perturbations can occur during the process and may have a direct impact over the metallurgical quality through the apparition of anomalies, which could reduce the calculated fatigue life. The aim of this study is to define a Process Monitoring technique able to detect the thickness affected by the machining taking into account the flank wear effect

Logical gaps

Catarina Dutilh Novaes on why we should dig into the cosmopolitan roots of logic

The enduring enigma of reason

In The Enigma of Reason, Mercier and Sperber (M&amp;S) present and defend their interactionist account of reason. In this piece, I discuss briefly the points of agreement between M&amp;S and myself and, more extensively, the points of disagreement, most of which pertain to details of the evolutionary components of their account. I discuss in particular the purported modular nature of reason; their account of myside bias as an optimum/adaptation; and the claim that reason thus construed must be an individual-level and not a group-level adaptation. In the final section, I offer brief considerations on an alternative account of reasoning, where the focus is on how sociocultural environments may tune the social production and evaluation of arguments.</p

Homecoming 2015

Photos of Homecoming 201

The (higher-order) evidential significance of attention and trust—comments on Levy’s Bad Beliefs

The work was supported by the H2020 European Research Council [ERC-2017-CoG 771074].In Bad Beliefs, Levy presents a picture of belief-forming processes according to which, on most matters of significance, we defer to reliable sources by relying extensively on cultural and social cues. Levy conceptualizes the kind of evidence provided by socio-cultural environments as higher-order evidence. But his notion of higher-order evidence seems to differ from those available in the epistemological literature on higher-order evidence, and this calls for a reflection on how exactly social and cultural cues are/count as/provide higher-order evidence. In this paper, I draw on the three-tiered model of epistemic exchange that I have been developing recently, which highlights the centrality of relations of attention and trust in belief-forming processes, to explicate how social and cultural cues provide higher-order evidence. I also argue that Levy’s account fails to sufficiently address the issue of strategic actors who have incentives to pollute epistemic environments for their benefit, and more generally the power struggles, incentives, and competing interests that characterize human sociality. Levy’s attempted reduction of the political to the epistemic ultimately fails, but his account of social and cultural cues as higher-order evidence offers an insightful perspective on epistemic social structures.Publisher PDFPeer reviewe

Two types of refutation in philosophical argumentation

This research was generously supported by the European Research Council with grant ERC-2017-CoG 771074 for the project ‘The Social Epistemology of Argumentation’.In this paper, I highlight the significance of practices of refutation in philosophical inquiry, that is, practices of showing that a claim, person or theory is wrong. I present and contrast two prominent approaches to philosophical refutation: refutation in ancient Greek dialectic (elenchus), in its Socratic variant as described in Plato’s dialogues, and as described in Aristotle’s logical texts; and the practice of providing counterexamples to putative definitions familiar from twentieth century analytic philosophy, focusing on the so-called Gettier problem. Moreover, I discuss Lakatos’ method of proofs and refutations, as it offers insightful observations on the dynamics between arguments, refutations, and counterexamples. Overall, I argue that dialectic, in particular in its Socratic variant, is especially suitable for the philosophical purpose of questioning the obvious, as it invites reflection on one’s own doxastic commitments and on the tensions and inconsistencies within one’s set of beliefs. By contrast, the counterexample-based approach to philosophical refutation can give rise to philosophical theorizing that is overly focused on hairsplitting disputes, thus becoming alienated from the relevant human experiences. Insofar as philosophical inquiry treads the fine line between questioning the obvious while still seeking to say something significant about human experiences, perhaps a certain amount of what Lakatos describes as ‘monster-barring’—a rejection of overly fanciful, artificial putative counterexamples—has its place in philosophical argumentation.Publisher PDFPeer reviewe