23 research outputs found
The effect of sodium and strontium on modification of eutectic silicon
Modification of eutectic (Ī±Al+Ī²Si) is usually performed during treatment of Al-Si based alloys in order to obtain higher mechanical properties. Chemical modification is usually performed using modifying elements such as Na and Sr. The research was performed in order to estimate the efficiency of Na and Sr additions in eutectic AlSi12 alloy using chemical analysis, simple thermal analysis (STA) and metallographic analysis. The metallographic analysis revealed fully modified (Ī±Al+Ī²Si) eutectic microstructure in alloy treated with Na. The Sr additions widened solidification interval and, lowered the eutectic area temperatures as indicated by STA
INTERMETALLIC BONDING BETWEEN A RING CARRIER AND AN ALUMINUM PISTON ALLOY
Abstract
This paper presents an analysis of the intermetallic bond between a ring carrier and an aluminum piston alloy. An optical microscope combined with the SEM / EDS analysis has been used to metallographically analyze the quality of the intermetallic bonding layer. The obtained results show that can be established intermetallic bond between two materials of different qualities
Influence of copper content on microstructure development of AlSi9Cu3 alloy
Microstructure development and possible interaction of present elements have been determined in charge material of EN AB AlSi9Cu3 quality. Literature review enables prediction of solidification sequence. Modelling of equilibrium phase diagram for examined chemical composition has been performed, which enables determination of equilibrium solidification sequence. Microstructural investigation indicated distribution and morphology of particular phase. Metallographic analysis tools enable exact determination of microstructural constituents: matrix Ī± Al, eutectic Ī±Al+Ī²Si, iron base intermetallic phase - Al5FeSi, Alx(Fe,Mn)yCuuSiw and/or Alx(Fe,Mn)yMgzCuuSiw and copper base phases in ternary eutectic morphology Al-Al2Cu-Si and in complex intermetallic ramified morphology Alx(Fe,Mn)yMgzSiuCuw. Microstructure development examination reveals potential differences due to copper content which is prerequisitefor high values of final mechanical, physical and technological properties of cast products
Influence of cooling rates on temperatures phase transitions and on microstructure of aluminium alloy EN AW-5083
The casting of different forms and dimensions of aluminium alloy EN WA-5083 test samples
and the usage of different types of mould materials resulted in achieving different cooling rates
of samples. The methods used were simple thermal analysis, using casting into a measuring cell
made by the Croning process and using casting into a cone-shaped measuring cell, as well as
simultaneous thermal analysis using the method of differential scanning calorimetry. Significant
temperature phase transitions and times of solidification were determined, and the
dependence model of the solidification time on the sample cooling rate was obtained. Determining
the mean number of grains per unit area on samples after having performed the simple
thermal analysis and differential scanning calorimetry makes it possible to develop a dependence
model of the mean number of grains per unit area on the cooling rate. These models are
the basis for carrying out numerical simulations of solidification and microstructure development
in the cone-shaped measuring cell, and the comparison of the distribution of the mean
number of grains per unit area obtained by simulation with the one obtained experimentally.
The obtained results represent a part of the preliminary tests of the microstructure development
of industrially cast ingots of EN AW-5083 alloy depending on the local ingot cooling rate.Beim GieĆen verschiedener Versuchsmuster mit unterschiedlichen Formen und GrĆen der Aluminiumlegierung
EN WA-5083 und Verwenden verschiedener Formstofftypen, wurden unterschiedliche
Abkhlgeschwindigkeiten festgestellt. Dabei wurde die Methode der einfachen Thermalanalyse
angewendet, die beim GieĆen in eine Messzelle einmal mit dem Croning-Verfahren
hergestellt wurde und einmal in eine kegelfrmige Messzelle gegossen wurde, samt gleichzeitiger
Thermalanalyse mit der Methode der differenziertenWrmemessung. Dabei wurden die Temperaturphasen
bergnge und Zeiten bis zur Erstarrung ermittelt sowie das Zeit-Modell in Abh
ngigkeit der Abkhlgeschwindigkeit bis zur Erstarrung der Versuchsprobe ermittelt. Durch die
Bestimmung des Mittelwertes der Anzahl der Krner pro Flche auf der Versuchsprobe nach der
durchgefhrten einfachen Thermalanalyse und der Methode der differenziertenWrmemessung,
kann ein Abhngigkeitsmodell des Mittelwertes der Anzahl der Krner pro Flche ber die Abk
hlgeschwindigkeit erstellt werden. Diese Modelle sind die Basis, um die numerische Simulation
des Festwerdens und die Mikrostruktur-Entwicklung in der kegelfrmigen messenden Zelle, samt
der Simulation des Vergleichs der Verbreitung des Mittelwertes der Anzahl von Krnern pro Fl-
che zu erlangen. Die erhaltenen Ergebnisse reprsentieren einen Teil der Forschung der Mikrostruktur-
Entwicklung beim industriellen GieĆen von Blcken der Legierung EN AW-5083 in Abh
ngigkeit der lokalen Abkhlgeschwindigkeit der Blcke
The effect of sodium and strontium on modification of eutectic silicon
Modification of eutectic (Ī±Al+Ī²Si) is usually performed during treatment of Al-Si based alloys in order to obtain higher mechanical properties. Chemical modification is usually performed using modifying elements such as Na and Sr. The research was performed in order to estimate the efficiency of Na and Sr additions in eutectic AlSi12 alloy using chemical analysis, simple thermal analysis (STA) and metallographic analysis. The metallographic analysis revealed fully modified (Ī±Al+Ī²Si) eutectic microstructure in alloy treated with Na. The Sr additions widened solidification interval and, lowered the eutectic area temperatures as indicated by STA
Identification of Phases Formed by Cu and Ni in Al?Si Piston Alloys
This paper presents the results of identifying and analyzing the phases present in the microstructure ofĀ 4 aluminum piston alloys with different chemical composition. Optical microscopy and scanning electronĀ microscopy were used to study the microstructure of the samples and EDS analysis was used to identify thecomposition of the phases. The phase stoichiometry was identified by comparing the results of EDS analysisĀ with the results reported in the studied literature. The results show that different intermetallic phases canĀ appear depending on the chemical composition of the microstructure of aluminum piston alloys
CANCER PATIENTS FOLLOW-UP ā CROATIAN SOCIETY OF MEDICAL ONCOLOGY CLINICAL GUIDELINES Part III: neuroendocrine neoplasms, hepatocellular carcinoma, pancreatic cancer, cancer of the bile ducts
LijeÄenje onkoloÅ”kih bolesnika mora se temeljiti na multidisciplinarnom pristupu, a provodi se u specijaliziranim onkoloÅ”kim centrima. Nakon zavrÅ”etka specifiÄnog onkoloÅ”kog lijeÄenja daljnje praÄenje uglavnom provode onkolozi, ali je uloga lijeÄnika primarne zdravstvene zaÅ”tite (PZZ) sve važnija i potrebno ju je jasno definirati. TrenutaÄno se veÄina preporuka za praÄenje ne temelji na prospektivnim studijama, veÄ se zasniva na struÄnim miÅ”ljenjima pojedinih onkoloÅ”kih centara ili specijalista. Hrvatsko druÅ”tvo za internistiÄku onkologiju (HDIO) ovim preporukama želi standardizirati i racionalizirati dijagnostiÄke postupke u praÄenju onkoloÅ”kih bolesnika, nakon zavrÅ”etka primarnog lijeÄenja, u bolesnika s neuroendokrinim neoplazmama, hepatocelularnim karcinomom, rakom guÅ”teraÄe i rakom žuÄnih vodova.The treatment of oncological patients must be based upon multidisciplinary approach, and takes place in specialized oncological centers. By the end of a specific oncological treatment further follow-up is being managed mostly by the oncologists, but the role of the general practitioners becomes more important every day and therefore should be precisely defined. Nowadays, most of the existing follow-up guidelines are not based on prospective studies, but on the experts opinion of individual oncological centers or specialists. The aim of the Croatian Society of Medical Oncology (CSMO) with these recommendations is to standardize and rationalize the diagnostic procedures algorithm in the follow-up of oncological patients after primary treatment, in patients with neuroendocrine neoplasms, hepatocellular carcinoma, pancreatic cancer and cancer of the bile ducts
PraÄenje onkoloÅ”kih bolesnika ā kliniÄke preporuke Hrvatskog druÅ”tva za internistiÄku onkologiju HLZ-a III. dio: neuroendokrine neoplazme, hepatocelularni karcinom, rak guÅ”teraÄe, rak žuÄnih vodova [Cancer patients follow-up ā Croatian society of medical oncology clinical guidelines Part III: neuroendocrine neoplasms, hepatocellular carcinoma, pancreatic cancer, cancer of the bile ducts]
The treatment of oncological patients must be based upon multidisciplinary approach, and takes place in specialized oncological centers. By the end of a specific oncological treatment further follow-up is being managed mostly by the oncologists, but the role of the general practitioners becomes more important every day and therefore should be precisely defined. Nowadays, most of the existing follow-up guidelines are not based on prospective studies, but on the experts opinion of individual oncological centers or specialists. The aim of the Croatian Society of Medical Oncology (CSMO) with these recommendations is to standardize and rationalize the diagnostic procedures algorithm in the follow-up of oncological patients after primary treatment, in patients with neuroendocrine neoplasms, hepatocellular carcinoma, pancreatic cancer and cancer of the bile ducts
CANCER PATIENTS FOLLOW-UP ā CROATIAN SOCIETY OF MEDICAL ONCOLOGY CLINICAL GUIDELINES Part III: neuroendocrine neoplasms, hepatocellular carcinoma, pancreatic cancer, cancer of the bile ducts
LijeÄenje onkoloÅ”kih bolesnika mora se temeljiti na multidisciplinarnom pristupu, a provodi se u specijaliziranim onkoloÅ”kim centrima. Nakon zavrÅ”etka specifiÄnog onkoloÅ”kog lijeÄenja daljnje praÄenje uglavnom provode onkolozi, ali je uloga lijeÄnika primarne zdravstvene zaÅ”tite (PZZ) sve važnija i potrebno ju je jasno definirati. TrenutaÄno se veÄina preporuka za praÄenje ne temelji na prospektivnim studijama, veÄ se zasniva na struÄnim miÅ”ljenjima pojedinih onkoloÅ”kih centara ili specijalista. Hrvatsko druÅ”tvo za internistiÄku onkologiju (HDIO) ovim preporukama želi standardizirati i racionalizirati dijagnostiÄke postupke u praÄenju onkoloÅ”kih bolesnika, nakon zavrÅ”etka primarnog lijeÄenja, u bolesnika s neuroendokrinim neoplazmama, hepatocelularnim karcinomom, rakom guÅ”teraÄe i rakom žuÄnih vodova.The treatment of oncological patients must be based upon multidisciplinary approach, and takes place in specialized oncological centers. By the end of a specific oncological treatment further follow-up is being managed mostly by the oncologists, but the role of the general practitioners becomes more important every day and therefore should be precisely defined. Nowadays, most of the existing follow-up guidelines are not based on prospective studies, but on the experts opinion of individual oncological centers or specialists. The aim of the Croatian Society of Medical Oncology (CSMO) with these recommendations is to standardize and rationalize the diagnostic procedures algorithm in the follow-up of oncological patients after primary treatment, in patients with neuroendocrine neoplasms, hepatocellular carcinoma, pancreatic cancer and cancer of the bile ducts
Utjecaj temperature žarenja na mikrostrukturu i tvrdoÄu AlSi10Mg dijelovaproizvedenih SLM aditivnim postupkom
SLM proizvodnja Co-Cr dentalnih legura je relativno novo podruÄje inženjerstva materijala. Utjecaj pojedinih parametara SLM postupka na strukturu i svojstva konsolidiranih Co-Cr dentalnih legura i njihova interakcija predstavlja važno podruÄje za istraživanje. Preliminarna istraživanja koja su provedena na proporcionalnim uzorcima izraÄenima od istog komercijalnog praha Co-Cr legure SLM postupkom na strojevima razliÄitih proizvoÄaÄa koristeÄi preporuÄene parametre postupka pokazala su velike razlike u mikrostrukturi dobivenih uzoraka te znaÄajna rasipanja vrijednosti mehaniÄkih svojstava konsolidiranog materijala (vlaÄna i savojna ÄvrstoÄa, istezanje i žilavost). Rasipanja rezultata nisu uoÄena samo izmeÄu uzoraka izraÄenih na razliÄitim strojevima, veÄ i izmeÄu uzoraka razliÄitih Å”arži na istom stroju. Dobiveni rezultati preliminarnih istraživanja pokazuju da u samoj proizvodnji Co-Cr legura SLM postupkom dolazi do utjecaja pojedinih parametara koji znaÄajno utjeÄu na kvalitetu dobivenog proizvoda. Ta povezanost glavnih tehnoloÅ”kih parametara SLM proizvodnje sa strukturom i svojstvima proizvoda i njihova interakcija je velikim dijelom nepoznato podruÄje i predstavlja veliki znanstveno istraživaÄki potencijal, gdje rezultati istraživanja mogu doprinijeti optimizaciji strukture i svojstava dentalnih Co-Cr legura. U ovom istraživanju planira se napraviti ispitivanje utjecaja pojedinih parametara DSLM postupka, i to snage lasera te brzine taljenja na mehaniÄka svojstva (vlaÄnu, tlaÄnu i savojnu ÄvrstoÄu) Co-Cr legure za dentalnu namjenu. TakoÄer Äe se napraviti i analiza mikrostrukture kojom Äe se utvrditi utjecaj pojedinih parametara na ispitivana mehaniÄka svojstva.SLM production of Co-Cr dental alloys is a relatively new field of materials engineering. The influence of individual parameters of the SLM procedure on the structure and properties of consolidated Co-Cr dental alloys and their interaction is an important area for research. Preliminary studies conducted on proportional samples made of the same commercial powder Co-Cr alloy SLM process on machines of different manufacturers using the recommended process parameters showed large differences in the microstructure of the obtained samples and significant differences in mechanical properties of consolidated material (tensile and flexural strength, elongation and toughness). Scattering of the results was observed not only between samples made on different machines, but also between samples of different batches on the same machine. The obtained results of preliminary research show that in the production of Co-Cr alloys by SLM process there is an influence of certain parameters that significantly affect the quality of the obtained product. This connection of the main technological parameters of SLM production with the structure and properties of products and their interaction is largely an unknown area and represents great scientific research potential, where research results can contribute to optimizing the structure and properties of dental Co-Cr alloys. In this research, it is planned to examine the influence of certain parameters of the DSLM procedure, namely laser power and melting rate on the mechanical properties (tensile, compressive and flexural strength) of Co-Cr alloy for dental purposes. A microstructure analysis will also be performed to determine the influence of individual parameters on the examined mechanical properties