Aluminum alloy impact sparkling

Abstract The cast machine parts are widely used in many branches of industry. A very important issue is gaining the appropriate knowledge relating to the application of castings in places of explosion risks including but not limited to mining, chemical industry and rescue works. A possibility of explosion risks occurrence following the impact sparkling of the cast metal parts is still not solved problem in scientific research. In relation to this issue, in this article, the results of the study are presented, and relating to the tendency to impact sparkling of the aluminium alloys used in machine building. On the grounds of the results obtained, it was demonstrated that the registered impact sparkles bunches of feathers from the analyzed alloys: AlSi7Mg, (AK7); AlSi9Mg, (AK9); AlSi6Cu4, (AK64) and AlSi11, (AK11) show significant differences between each other. The quantitative analysis of the temperature distribution and nuclei surface area performed on the example of the alloy AK9 (subjected to defined period of corrosion) allows for the statement that they are dangerous in conditions of explosion risk. Following this fact, designers and users of machine parts made from these materials should not use them in conditions where the explosive mixtures occur

Decoding reactive structures in dilute alloy catalysts

Rational catalyst design is crucial toward achieving more energy-efficient and sustainable catalytic processes. Understanding and modeling catalytic reaction pathways and kinetics require atomic level knowledge of the active sites. These structures often change dynamically during reactions and are difficult to decipher. A prototypical example is the hydrogen-deuterium exchange reaction catalyzed by dilute Pd-in-Au alloy nanoparticles. From a combination of catalytic activity measurements, machine learning-enabled spectroscopic analysis, and first-principles based kinetic modeling, we demonstrate that the active species are surface Pd ensembles containing only a few (from 1 to 3) Pd atoms. These species simultaneously explain the observed X-ray spectra and equate the experimental and theoretical values of the apparent activation energy. Remarkably, we find that the catalytic activity can be tuned on demand by controlling the size of the Pd ensembles through catalyst pretreatment. Our data-driven multimodal approach enables decoding of reactive structures in complex and dynamic alloy catalysts

Zmniejszenie entropii i prostota jako zasady maszynowego rozpoznawania wzorców w ujęciu Satosi Watanabego

Philosophers are motivated to do research concerning pattern recognition because of wide range of its applications. One of the pathfinders of research in that area was Satosi Watanabe, who has been frequently commented in the literature concerning this subject. The rule of decrease in entropy and the rule of simplicity are described in the context of pattern recognition. Although the concept of entropy had been initially used in the area of thermodynamics, it could be adopted also in the field of pattern recognition. The concept of entropy should be then suitable transformed. A few of examples of the entropy concept application and the relationship between entropy and simplicity are discussed in the article. Simplicity considered by Watanabe should be treated mainly as polynomial curve simplicity, however the issue is described in the wider contex

Wpływ obróbki powierzchniowej na zużycie szyjki okładziny wrzecion przędzalniczych z nasadką antybalonową

The paper presents test results of the effect of the surface treatment type on the wear of spindle-neck coating with a collapse balloon crown of ring spinning frames within industrial conditions of mating with yarn. The tests comprised measurements, using the optical method, of spindle-neck coating produced from EN AW-2024 (AlCu4Mg1) alloy, and subjected to, in the first variant, the operation of burnishing, and in the second variant – the burnishing operation followed by hard anodic oxidation and grinding with abrasive paper having a grain size of 600. Moreover, to be able to do it, the circularity deviation of the cylindrical part of the neck coating at the same distances from the face of the crown were measured with the use of a Taylrond 365 circularity tester. Next, based on the contours of circularity obtained, a contour of cylindrical shape of the spindle-neck coating, both burnished and burnished and anodic oxidized, brand-new and after an operational time was prepared. An assessment of the topography and microphotography of the oxide layer of the spindle-neck coating was performed, both in brand-new condition and after an operational time. Analysis of the wear and tear process, as well as the thickness of the oxide layer, in brand-new condition and after an operational time, confirmed that the oxide layer assures a wear-resistance several times higher. As a result of the hard anodic oxidation implemented, equalisation of the durability of the spindle-neck coating occurres with the durability of the bearing system.W artykule zamieszczono wyniki badań wpływu rodzaju obróbki powierzchniowej na zużycie szyjki okładziny wrzecion z nasadką antybalonową przędzarki obrączkowej przy współpracy z przędzą w warunkach przemysłowych. Badania objęły pomiary, metodą metryczną, zużycia szyjki okładziny wrzecion wykonanych ze stopu EN AW-2024 (AlCu4Mg1) i poddanych, w pierwszym wariancie, operacji nagniatania oraz w drugim - nagniatania i następnie utleniania anodowego twardego oraz szlifowania papierem ściernym o wielkości ziarna 600. Ponadto w tym celu wykonano pomiary odchyłki okrągłości części walcowej szyjki okładziny, w równych odstępach od czoła nasadki, za pomocą okrągłościomierza Taylrond 365. Następnie na podstawie uzyskanych zarysów okrągłości sporządzono zarys walcowości szyjki okładziny wrzeciona nagniatanej oraz nagniatanej i utlenianej anodowo, przed i po czasie eksploatacji. Wykonano również ocenę topografii i mikrofotografii powierzchni oraz mikrostruktury warstwy tlenkowej szyjki okładziny wrzecion przędzalniczych, przed i po okresie eksploatacji. Analiza przebiegu procesu zużywania się oraz grubości warstwy tlenkowej przed i po okresie eksploatacji potwierdza, że warstwa tlenkowa zapewnia kilkukrotny wzrost odporności na zużycie. W efekcie zastosowania utleniania anodowego twardego następuje zrównanie trwałości szyjki okładziny wrzeciona z trwałością wkładu łożyskowego

The multicriteria optimization algorithms of manufacturing processes structure

W artykule przedstawiono etapy wielokryterialnej optymalizacji struktury procesów wytwarzania. W szczególności scharakteryzowano najczęściej stosowane algorytmy w wielokryterialnej optymalizacji struktury procesów wytwarzania, uwzględniające w ocenie: tylko subiektywne kryteria punktowe, tylko subiektywne kryteria względne, tylko kryteria deterministyczne oraz algorytm uwzględniający wszystkie rodzaje kryteriów tj. kryteria deterministyczne, probabilistyczno-statystyczne i rozmyte. W podsumowaniu zamieszczono zalety i wady przedstawionych algorytmów.This paper presents the multicriteria optimization procedure of manufacturing processes. The optimization model of processes structure which take into account deterministic and fuzzy assessment criteria is described. Two stage of parametric optimization of manufacturing processes are analyzed. In the first stage, the Pareto set on account of two criteria with the aid of weighting method is generated. In the second stage, the best solution with the aid of lexicographic method is selected. In the summary are given the advantages and disadvantages of the presented algorithms