| 1. |
- Hrechuk, Andrii, et al.
(författare)
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Novel metric “Implenarity” for characterization of shape and defectiveness : The case of CFRP hole quality
- 2021
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Ingår i: Composite Structures. - : Elsevier BV. - 0263-8223. ; 265
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Tidskriftsartikel (refereegranskat)abstract
- Image Processing is rapidly expanding as a technique for object and defect analysis because of the high ease of its coupling to automation and IT solutions. Yet, issues with transferability of the measurement approaches and metrics currently used in mechanical systems often remain unsolved. Study reports on the developed approach for shape and defectiveness characterization by combining Delaunay triangulation of object's contour with uniformity analysis of triangles in the generated mesh using developed metric “Implenarity”. When analyzing hole drilling in CFRP, experimental validation found that for highest quality of CFRP holes, implenarity shifts from its maximum of I = 0.22 for a circle to I ≈ 0.16 for microdefects below 100 µm—normally not quantifiable with conventional techniques. In presence of larger hole defects, implenarity demonstrated similar capabilities to standard metrics, but avoided their inherent flaws. Implenarity continued distinguishing degree of defectiveness for the same area of uncut fibers (Fa-cov) and the same delamination diameter (Fd,Fda).
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| 2. |
- Moreno, Maiara, et al.
(författare)
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Adhesive wear of TiAlN coatings during low speed turning of stainless steel 316L
- 2023
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Ingår i: Wear. - : Elsevier BV. - 0043-1648 .- 1873-2577. ; 524-525
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Tidskriftsartikel (refereegranskat)abstract
- The wear behavior of TiAlN coatings during turning of stainless steel 316L at low cutting speeds (60–120 m/min) was investigated using scanning electron microscopy. In this speed range, the coatings fail by fracture due to an adhesive wear mechanism. The fracture of the coating is described in detail, including the strong influence of Al-content and cutting speed on the rate of wear. Low Al-content (x ≤ 0.23) coatings showed worse wear resistance than high Al-content (x ≥ 0.53) samples. Less substrate is exposed when the cutting speed is increased, because of reduced adhesive wear. The TiN and Ti0.77Al0.23N coatings are severely worn for all cutting speeds while Ti0.47Al0.53N and Ti0.38Al0.62N remain essentially unaffected at the highest speed. The difference in wear behavior is interpreted as a difference in the fracture toughness of the coatings.
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| 3. |
- Ståhl, Jan Eric, et al.
(författare)
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Relationship Between Tool Temperature Distribution and Stagnation Point Behavior for Different Process Factors in Machining Operations
- 2024
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Ingår i: Moving Integrated Product Development to Service Clouds in the Global Economy - Proceedings of the 21st ISPE Inc. International Conference on Concurrent Engineering, CE 2014. - 2352-751X .- 2352-7528. - 9781643685106 ; 52, s. 69-89
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Konferensbidrag (refereegranskat)abstract
- Metal cutting is physically defined by a tool separating a chip by developing a stagnation point after the work material has passed a shear plane. This distinguishes the method group metal cutting or machining from shearing and wedging processes. The development of the stagnation point is central to the functioning of a metal cutting process. The stagnation point and its behavior has a great influence on the different load conditions of the tool as it controls both the temperature distribution and the mechanical load distribution around the tool's edge-line. This publication shows that there is a temperature drop at the stagnation point where the shear stress changes sign, which means that the shear stress at this point assumes the value zero. Furthermore, it is demonstrated that there is a correlation between the position of the temperature dip, its size and the selected cutting data as well as tool geometry and current work material. The knowledge of the interaction between the position of the stagnation point and the tool coating type in combination with the tool's micro- and macro-geometry will be of importance for the development of high-performance tools optimized for different machining applications.
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