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1
Content available remote Welding thermal cycles of joints made of S1100QL steel by saw and hybrid plasma-mag processes
Sajek A.
Advances in Materials Science
|
2020
|
Vol. 20, nr 4(66)
75--86
EN
The aim of this article is to validate the method of conducting a multipoint temperature measurement in the area of welded joints as a tool for quality assessment of the joints in question. In order to establish a relationship between temperature readout at a given point, the value of heat input and the distance of the point form the weld axis, preliminary tests have been conducted on a set of padding welds. Correlation of measurement data analysis showed the high 0.99 level. In the second stage of the study, temperatures of joints welded with two different methods have been measured: the HPAW (Hybrid Plasma – Arc Welding) and classic SAW (Submerged Arc Welding) method. The obtained temperature curves reflect the intensity of heat input in a given welding process. When compared to thermal effects on metallographic specimens, the shapes of the curves show a potential for quality assessment of joints in production conditions. Estimating thermal effects with classic analytical methods proves imprecise with respect to advanced high-power welding processes. Monitoring temperature will allow to assess the quality of joints in the course of welding, which may be a remarkable factor in terms of limiting the HAZ (heat affected zone) tempering of joints made from MART steels (advanced high strength martensitic steel) – a phenomenon that exceedingly decreases the strength of the joints. The method for quality assessment of welded joints presented in this paper allows to extend the analysis of welding thermal conditions.
2
Content available remote Impact Tests of UHSS Steel Welded Joints Using the Drop - Tower Impact Drop Method
Dorożyński J., Nowacki J., Sajek A.
Advances in Materials Science
|
2019
|
Vol. 19, nr 3(61)
19--31
EN
The article characterizes the impact test method using Drop-Tower Impact Test with the registration of the value of force and energy of breaking. Based on sources, the possibilities and scope of the current application of this method were determined and the current state of knowledge on the results of these tests was reviewed. In order to determine the possibility of using the method in impact tests of high strength steel joints, investigations of hybrid PTA - GMA welding conditions on impact strength of joints of MART S1300QL steel were carried out. In particular, the influence of t8/5 cooling time on the impact strength of welded joints by the Drop - Tower Impact Test method was determined. It has been shown that the use of dropping machine with computer-based registration of breaking force and energy values was possible in the case of impact strength testing of UHSS welded joints and enabled precise analysis of the energy distribution dynamics absorbed by the tested.
3
Content available remote Verification of Properties of Joints Made of Advances High Strength Steels in the Conditions of the Complex Thermal Cycles of the HPAW Process
Nowacki J., Sajek A.
Biuletyn Instytutu Spawalnictwa w Gliwicach
|
2018
|
Vol. 62, No. 5
167--173
EN
The article discusses the primary issue related to the verification of properties of joints made in AHSS in relation to conventional structural steels and based on the identification of cooling time t8/5. The solution suggested in the study involving the application of the Finite Element Method is based on two computational models. In addition the article presents a material model allowing for properties of single metallic phases and their interaction during the welding cycle. The study also describes the numerical model of the HPAW (plasma + MAG) heat source composed of two models predefined in the Simufact.Welding software programme corresponding to the nature of constituent processes. The research-related tests also involved welding simulations and experimental verification. The tests demonstrated the conformity of simulation results and the high usability of simulation when verifying properties of joints.
PL
Scharakteryzowano podstawowy problem kontroli właściwości złączy wykonanych ze stali AHSS w odniesieniu do konwencjonalnych stali konstrukcyjnych, bazujący na wyznaczaniu czasu stygnięcia t8/5. Zaproponowane rozwiązanie w postaci zastosowania metody elementów skończonych bazuje na dwóch modelach obliczeniowych. Przedstawiono model materiałowy, który uwzględnia właściwości pojedynczych faz metalicznych oraz ich interakcje w trakcie cyklu spawania. Jako drugi, opisano numeryczny model hybrydowego źródła ciepła HPAW (plazma + MAG) składający się z dwóch predefiniowanych w oprogramowaniu Simufact.Welding modeli, adekwatnych do charakterów procesów składowych. Przeprowadzono symulację spawania oraz eksperyment weryfikujący. Wykazano zgodność wyników symulacji i jej wysoką przydatność w zakresie kontroli właściwości analizowanych złączy.
4
Content available remote Comparative evaluation of various experimental and numerical simulation methods for determination of t8/5 cooling times in HPAW process weldments
Sajek A., Nowacki J.
Archives of Civil and Mechanical Engineering
|
2018
|
Vol. 18, no. 2
583--591
EN
The aim of this article is to provide a quantitative comparison and efficiency verification of the methods of estimating t8/5 cooling time in the process of HPAW of S960QL steel. The measurements of t8/5 welding time were conducted at the face of weld with the use of thermoelectric, pyrometric and thermovision methods. A FEM model of the joint was made, and welding simulation was done. The results of the calculations were then confronted with experimental data, and measuring methods were evaluated. Differences in the results of t8/5 time measurements were determined for the analysed methods and arranged according to the precision of results presented; the applicability of FEM for predicting the value of t8/5 time was investigated. The usability of temperature measuring methods for determining cooling time was determined, the weaknesses of non-contact measurement in terms of diversification of cooling time in a section of a welded joint were shown, and the advantages of numerical method were demonstrated. It was established that joining experimental methods for measuring cooling time of a joint with FEM analysis allows to obtain a desired resolution of prediction. In this way, the technology for hybrid welding of advanced high-strength steels can be designed more efficiently.
5
Content available remote Zastosowania metody elementów skończonych w analizie spawania hybrydowego PAW-MAG
Nowacki J., Sajek A.
Stal, Metale & Nowe Technologie
|
2016
|
nr 9-10
26--30
PL
W artykule przedstawiono problematykę symulacji procesu spawania przy użyciu metody elementów skończonych i dedykowanego do tego procesu specjalistycznego oprogramowania simufact.welding. Zaprezentowano przykładowe wyniki obliczeń numerycznych stali o zróżnicowanych właściwościach spawanych metodą hybrydową PAW-MAG oraz zakres możliwości symulacji nowoczesnej i innowacyjnej metody spawania hybrydowego PAW-MAG, wspomagające optymalny dobór parametrów we wczesnej fazie wprowadzania nowego produktu. Zaprezentowano wyniki modelowania rozkładu temperatury, struktury, twardości, naprężeń i odkształceń w złączu oraz duże zróżnicowanie modeli materiałowych zaimplementowanych w wykorzystanym w badaniach środowisku obliczeniowym oraz określono możliwości Metody Elementów Skończonych w analizie historii cieplnej dowolnego obszaru złącza spawanego, dowodzące, że stanowi ona innowacyjne narzędzie projektowania złączy spawanych stali.
EN
The article presents the issue of simulating the welding process using the finite element method and the specialized software simufact.welding dedicated to this process, as well as the exemplary results of the numerical calculations of steels of different properties welded using PAW-MAG – a modern and innovative method of hybrid welding – and the range of its simulation capabilities supporting the optimal selection of parameters in the early phase of a product introduction. Moreover, it addresses the results of the modelling of temperature distribution, structure, hardness, stress and strain in the joint and a large diversity of material models implemented in the computing environment used in the research and identifies the possibilities of the element method in the analysis of the thermal history of any area of the welded joint proving that it constitutes an innovative tool for the design of welded joints of steel.
6
Content available remote Optimizing glue joint of aluminium metallic foams
Nowacki J., Sajek A.
Journal of Achievements in Materials and Manufacturing Engineering
|
2016
|
Vol. 75, nr 1
14--23
EN
Purpose: Characteristics of aluminium foams as construction material were given, along with some exemplary applications. The purposefulness of lowering the mass of constructions comprising aluminium foams was discussed, and bonding techniques as well as prospects of reducing the mass of a joint were analysed. A computer simulation was performed for a representative fragment of a glue joint in aluminium foam with the purpose of analyzing existing stresses for three variants of thickness of a layer of epoxy glue. Design/methodology/approach: Preliminary tests on the complete test specimen were conducted, and then a new model of a joint was made, based on a small part of the geometry of the joint. The methodology employed allowed for a precise investigation of the working conditions of a glue joint in a statics hear test depending on the thickness of a layer of glue. Findings: A high interdependence between stresses in a metallic foam and the thickness of a glue joint was observed – the thicker the layer of glue, the stiffer the joint. The thickness of the glue layer inspected in the simulation does not influence the strength of the joint. Research limitations/implications: The tests were conducted with the use of an improved yet simplified model of a joint that allowed to determine stresses present both in metallic foam and in the weld. Further course of action in the modelling of glue joints was set with the aim of establishing a more detailed definition of weld work conditions. Practical implications: Basic factors affecting the efficiency of joining aluminium foams by means of gluing were defined, and guidelines concerning the technology for producing a proper joint were given. Originality/value: A problem concerning gluing aluminium foams with regard to mass optimization was highlighted. A mechanism for minimizing stresses in the structure of a weld through the regulation of weld thickness was presented.
7
Content available remote Numerical simulation the thermal cycle of the PAW-MAG hybrid welding of advanced high strength steels
Nowacki J., Sajek A.
Biuletyn Instytutu Spawalnictwa w Gliwicach
|
2016
|
Vol. 60, No. 6
13--19
PL
Zbadano możliwość wyznaczania czasu t8/5 za pomocą metody elementów skończonych. Badaniom poddano modelowe złącze spawane metodą hybrydową PAW-MAG ulepszanych cieplnie stali AHSS S960QL. Porównano czas t8/5 dla charakterystycznych stref złącza przy stałej ilości wprowadzonego ciepła. Dostrzeżono istotne różnice w szybkości stygnięcia wynikające ze zróżnicowanej geometrii złącza i niesymetrycznej dystrybucji ciepła. Zdefiniowano możliwości metody elementów skończonych z zastosowaniem modelowania przestrzennego w badaniu historii cieplnej dowolnego obszaru złącza spawanego. W wyniku porównania analizowanego sposobu określania czasu t8/5 z tradycyjnymi metodami pomiarowymi i analitycznymi wykazano znacząca przewagę MES polegającą na dokładnej i całościowej indukcji cyklu w całym przekroju złącza w przeciwieństwie do eksperymentalnych metod stykowych i bezstykowych, które uśredniają pomiar na jego powierzchni lub tylko w osi spoiny. W aspekcie różnic w czasie t8/5 sięgających 1,5 s w obszarze złącza i bardzo wąskiego zakresu tolerancji wartości czasu stygnięcia stali AHSS ulepszanej cieplnie, uznano metodę elementów skończonych z zastosowaniem modelowania przestrzennego za niezbędne narzędzie do projektowania złączy spawanych stali AHSS.
EN
The research described in the article was concerned with the possibility of determining time t8/5 using the Finite Element Method. The research-related tests involved a joint made of AHSS S960QL using the PAW-MAG method. Values of time t8/5 were compared in relation to characteristic zones of the joint and constant heat input values. Differences in cooling rates related to the diversified geometry of a joint and the asymmetric distribution of heat proved significant. The research involved the identification of possibilities offered by the Finite Element Method involving space modelling in the examination of the thermal history of any welded joint area. The comparison of the analysed manner of determining time t8/5 with traditional measurement and analytical methods revealed the significant advantage of the FEM consisting in the accurate and complete induction of a cycle in the entire cross-section of the joint in contrast with experimental contact and non-contact methods averaging the measurement on the joint surface or only in the weld axis. In view of differences related to time t8/5 reaching 1.5 seconds in the joint area and the very narrow range of the tolerance concerning the value of the cooling time of AHSS, the Finite Element Method involving the use of space modelling was recognised as a necessary tool when designing welded joints made of Advanced High Strength Steels.
8
Content available remote The influence of welding heat input on the microstructure of joints of S1100QL steel in one-pass welding
Nowacki J., Sajek A., Matkowski P.
Archives of Civil and Mechanical Engineering
|
2016
|
Vol. 16, no. 4
777--783
EN
Microstructure transformations of a welded joint of the of quenched and tempered advanced high-strength S1100QL steel in relation to the heat input and its effect on the strength of the joint. The gas metal arc welding method was used with varying values of the heat input in the range from 5.5 to 7.1 kJ/cm. Metallographic examination, hardness, impact strength, and tensile strength tests were carried out. Innovative methodology of welding impact test using drop tower impact resistance tester, has been applied. Joints with strength higher than that of welded steel were created. The amount of heat input necessary to produce joints of S1100QL steel whose strength would be higher than that of parent material was determined. The advantages of using S1100QL steel were indicated and a method of one-pass welding that allows for production of joints of optimum strength parameters with the use of mismatched filler metals was presented. As the result of detailed weld cracking dynamics analysis of the S1100QL steel the course of joint deformation was determined as a function of time, loading force and impact energy. It was found that the dynamically loaded samples welded with lower heat input display higher limit of elasticity, which is manifested by higher loading forces and longer deformation time.
9
Content available remote Wpływ utwardzenia krawędzi ciętej na właściwości wytrzymałościowe złącza spawanego
Pakos R., Sajek A.
Przegląd Spawalnictwa
|
2014
|
R. 86, nr 9
19--23
PL
W artykule przedstawiono wpływ cięcia termicznego i związanego z tym procesem utwardzenia krawędzi ciętej na właściwości mechaniczne złączyspawanych. Wykorzystano cztery warianty krawędzi ciętej stali S690QL. Zastosowano cięcie tlenem i cięcie plazmą. Spawano złącza bez dodatkowej obróbki i złącza po zeszlifowaniu 1 mm krawędzi. Przeprowadzono badania udarności i wytrzymałości na rozciąganie. Wykazano wpływ przygotowania złącza na jego właściwości mechaniczne.
EN
The paper presents the influence of thermal cutting and the related process of hardening the cut edge on the welded joints mechanical properties. Four variants of the cut steel S690QL edge was used. Applied oxygen and plasma cutting. Joints without additional processing and joints after removing 1 mm edge were welded. Impact tests and tensile strength were performed. Shows the effect of joint preparation for the mechanical properties.
10
Content available remote Technologia klejenia i właściwości złącza klejowego kompozytowych pian aluminiowych
Sajek A.
Przegląd Spawalnictwa
|
2014
|
R. 86, nr 3
47--54
PL
W artykule przedstawiono przykład rozwiązania konstrukcji złącza klejowego piany aluminiowej wykonanego przy użyciu dwuskładnikowego kleju epoksydowego. Sformułowano założenia dla złącza dotyczące rozkładu sił i naprężeń w rozciąganej próbce. Ustalono zalecenia do przygotowania powierzchni pian, procedurę klejenia uwzględniającą kontrolę porowatości piany i chropowatości klejonej powierzchni blachy. W wyniku badań wytrzymałościowych określono mechanizm niszczenia złącza. Zaproponowano optymalizację konstrukcji złącza poprawiającą jego właściwości.
EN
The paper presents an example of design solution of aluminum foam glue joint using two-component epoxy glue. The joint principles for distribution forces and stresses in the tensile sample were formulated. Recommendations for surface preparation of foam and gluing procedure aimed at control the porosity of the foam and glued surface roughness were established. As a result of strength tests defined joint destruction mechanism was proposed. It was suggested that optimized joint design improving its properties.
11
Content available remote Welding of MART steel with the use of matching fillers
Matkowski P., Nowacki J., Sajek A.
Archives of Materials Science and Engineering
|
2014
|
Vol. 70, nr 2
77-86
EN
Purpose: This paper attempts to determine the influence of using fillers of various kinds on strength of a welded joint of MART steel depending on the amount of heat supplied. Design/methodology/approach: Test welded joints were made of S1100QL steel with GMAW method, and using different fillers as well as different values of supplied heat. The tests were designed in such a way so as to demonstrate the prospected interdependencies as clearly as possible. Macroscopic examination was carried out, Vickers hardness, impact strength and tensile strength were measured, and technological bend test was conducted on the joint. Findings: Significant differences between the joints obtained resulting from the fillers used and welding parameters applied were noticed. The strength of a joint is lower than that of welded steel, it concentrates in the weld and is similar to the strength of parent material. Research limitations/implications: Conducting research concentrating on welding using particular filler in a wider range of heat supplied would make it possible to obtain more precise results. By delineating the interdependencies between strength parameters, it would be possible to optimise the mechanical properties of welded joints made of MART steels. It would require the employment of automated welding that allows for unrestricted and stable control of parameters. Practical implications: The conditions for making a proper joint of S1100QL steel were determined. Reasons were given for the choice of joint testing methodology and the purposefulness of comprehensive tests of joint parameters. The need for changing test procedures in order to eliminate the causes of inappropriate evaluation was manifested. The influence of automation as an important factor that determines the fulfilment of strict parameter regime of joint formation was emphasised. Determination of the interrelations between mechanical properties of a joint and welding parameters applied would allow to conduct a welding process in such a way so as to obtain a joint of desired usefulness in given technological conditions. Originality/value: Problems associated with welding of S1100QL steel with the use of filler metals of matching materials were defined and possible solutions for these problems were presented. The mechanism of welding thermal cycle influencing structural changes in the joint that result from the complex cycle of hardening and tempering was demonstrated.
12
Content available Aluminium foams gluing
Sajek A.
Metallurgy and Foundry Engineering
|
2013
|
Vol. 39, no. 2
15--22
EN
The paper presents an example of design solution of aluminum foam glue joint using two-component epoxy glue. The joint principles for distribution forces and stresses in the tensile sample were formulated. Recommendations for surface preparation of foam and gluing procedure aimed at control the porosity of the foam and glued surface roughness were established. As a result of strength tests defined joint destruction mechanism was proposed. It was suggested that optimized joint design improving its properties.
XX
W artykule przedstawiono przykład rozwiązania konstrukcji złącza klejowego piany aluminiowej wykonanego za pomocą dwuskładnikowego kleju epoksydowego. Sformułowano założenia dla złącza dotyczące rozkładu sił i naprężeń w rozciąganej próbce. Ustalono zalecenia do przygotowania powierzchni pian, procedurę klejenia uwzględniającą kontrolę porowatości piany i chropowatości klejonej powierzchni blachy. W wyniku badań wytrzymałościowych określono mechanizm niszczenia złącza. Zaproponowano optymalizację konstrukcji złącza poprawiającą jego właściwości.
13
Content available remote Mechanical analysis and numerical simulation of modified bone cements in the hip joint alloplasty
Nowacki J., Sajek A.
Journal of Achievements in Materials and Manufacturing Engineering
|
2011
|
Vol. 46, nr 1
57--64
EN
Purpose: The paper aims at verifying the stress values in bone-cement-implant system during human movement cycle and determining the amount of bone cement admixture which induces a drop in mechanical properties to acceptable level. Design/methodology/approach: In the first place, mechanical tests of modified cements were carried out. These tests are a basis for mathematical description of mechanical properties which will be used during numerical simulations. Numerical simulations were carried out using the geometry obtained by computer tomography. Findings: A drop in mechanical properties induced by modification depends on admixture size. During movement, cement bond is affected by considerable forces. These forces operate cyclically, i.e. momentarily (when setting a foot on the ground) within the elastic range of examined material. From the point of view of mechanical parameters, an optimum admixture of the aqueous solution of biologically active modifying agent is that inducing porosity at a level of 8%. Research limitations/implications: The paper constitutes a beginning of examinations on modified cement junctures which may be expanded in future by testing the dynamics basing on the analysis of fatigue strength. Practical implications: Modifying agent amount was determined and verified that does not induce a decrease in the bending strength and the longitudinal modulus of elasticity during bending below the level specified in ISO 5833 standard. Originality/value: Modification of cement with aqueous solution of salmon calcitionin, as well as examination and verification of the effect of admixture on mechanical properties.
14
Content available remote Modified bone cement microstructure numeric simulation
Nowacki J., Sajek A.
Journal of Achievements in Materials and Manufacturing Engineering
|
2010
|
Vol. 43, nr 2
533--541
EN
Purpose: The paper aimed at determining the strength of modified bone cement microstructure. Modification with aqueous hormone solution stimulates the growth of bone at a hip-joint endoprosthesis implantation site. Design/methodology/approach: In the first place, microstructure of modified cements was examined. This examination was a basis for statistical description of porosity obtained as a result of modification. Statistical data were used to create microstructure models in a programme being in agreement with FEM technique. Simulations were carried out on structures of 2 types of pores, i.e. those containing water and empty ones. Findings: Modification with aqueous solutions of modifying agents affects the structure and properties of bone cements. This is caused by formation of pores filled with aqueous solutions of modifying agents. This type of porosity decreases mechanical properties less than air-filled pores. Research limitations/implications: Numerical simulation of the stress and displacement pattern in juncture microstructure should be expanded with a simulation of bone-cement-implant system operation, which will allow estimation of an optimum value of modifying agent admixture, i.e. a value enabling the improvement of juncture biocompatibility not lowering at the same time its mechanical properties below a level set up in standard specifications. Practical implications: Microstructure simulations performed confirmed a manner of modified cement cracking observed on fractures. They showed formation of pore agglomerations where concentrating stresses may bring about the appearance of dangerous micro-fractures. Originality/value: Cement modification with aqueous solution and examination of the effect of admixture on microstructure mechanical properties.
15
Numerical simulation of microstructure and internal stresses of the modified bone cement
Nowacki J., Sajek A.
Inżynieria Materiałowa
|
2010
|
Vol. 31, nr 3
728-731
EN
Microstructure of bone cement modified by an aqueous solution of an enzyme - salmon calcitionin was considered. A statistical description of the porosity of obtained cements as a result of the modification has been done. Statistical data were used to create the microstructure models in a programme being in agreement with FEM technique. Simulations were carried out on the structures of two types of pores, i.e. those containing water and empty ones. Modification with aqueous solutions of agents affects the structure and properties of the bone cements were observed. This is caused by the formation of pores filled with the aqueous solution. Microstructure simulations confirmed a manner of modified cement cracking was observed on the fractures. The formation of pore agglomerations where concentrating stresses may bring about the appearance of dangerous microfractures was proved.
PL
Analizowano mikrostrukturę cementu kostnego nowej generacji modyfikowanego wodnym roztworem enzymu - kalcytoniny łososiowej, stosowanego w aloplastyce stawu biodrowego. Wykonano statystyczny opis porowatości cementu po modyfikacji, stanowiący podstawę opracowania metodą elementów skończonych modelu mikrostruktury cementu. Wykazano, że domieszkowanie wodnymi roztworami modyfikatorów ma wpływ na mikrostrukturę i właściwości cementów kostnych. Spowodowane jest to tworzeniem porów wypełnionych wodnymi roztworami modyfikatorów i powietrzem. Pierwszy rodzaj porowatości w mniejszym stopniu niż pory wypełnione powietrzem zmniejsza właściwości mechaniczne cementów. Wykazano powstawanie aglomeracji porów, w których koncentrujące się naprężenia mogą powodować pojawianie się mikropęknięć.
16
Content available remote Wybrane aspekty spajania biomateriałów
Nowacki J., Sajek A.
Przegląd Spawalnictwa
|
2009
|
R. 81, nr 11
8-14
PL
Przedstawiono wybrane aspekty spajania biomateriałów. W obszarze eksperymentu określono mikrostrukturę i wytrzymałość domieszkowanego cementu kostnego, traktowanego jako spoiwo w implantacji endoprotezy w tkance kostnej. Domieszkowanie wodnym roztworem hormonu stymuluje wzrost kości w miejscu implantacji endoprotezy stawu biodrowego. Wykonano badania mikrostruktury domieszkowanych cementów. Badania te są podstawą do opisu statystycznego uzyskanej w wyniku domieszkowania porowatości. Dane statystyczne zostały wykorzystane do utworzenia modeli mikrostruktury w programie w konwencji MES. Symulacje prowadzono na strukturach dwóch typów porów: zawierających wodę i pustych. Wykazano, że domieszkowanie wodnymi roztworami modyfikatorów ma wpływ na strukturę i właściwości cementów kostnych. Spowodowane jest to tworzeniem porów wypełnionych wodnymi roztworami modyfikatorów. Ten rodzaj porowatości w mniejszym stopniu niż pory wypełnione powietrzem zmniejsza właściwości mechaniczne. Przeprowadzone symulacje mikrostruktury potwierdziły sposób pękania domieszkowanego cementu zaobserwowanego na przełomach. Ukazały powstawanie aglomeracji porów, w których koncentrujące się naprężenia mogą powodować pojawianie się groźnych mikropęknięć.
EN
Selected aspects of biomaterials bonding have been presented. In the range of the experiment, microstructure and strengths of doped bone cement treated as a binding material in implantation of an endoprothesis in osseous tissue have been determined. Doping with the water solution of a hormone stimulates growth of a bone in the place of implantation of a hip joint endoprothesis. Tests of microstructure of cements doped have been executed. Those tests make a base for statistical description of porosity obtained as a result of doping. Statistical data have been used to create microstructure models in the program in the MES convention. Simulations have been performed on structures of two types of pores: pores containing water and empty pores. It has been pointed out that doping with water solutions of modifying agents affected the structure and properties of bone cements. It is caused by formation of pores filled with water solutions of modifying agents. That type of porosity decreases mechanical properties in lower degree than pores filled with air. Microstructure stimulations, which have been performed, confirmed a way of cracking of doped cements observed in fractures. They showed arising of pores agglomerations, were concentrating stresses may cause occurring of dangerous microcracks.
17
Content available remote Szczeciński Ośrodek Kształcenia Międzynarodowych Inżynierów Spawalników
Nowacki J., Sajek A., Szefner Z.
Przegląd Spawalnictwa
|
2008
|
R. 80, nr 11
35-38
PL
Przedstawiono charakterystykę Szczecińskiego Ośrodka Szkolenia i Certyfikowania Międzynarodowych Inżynierów Spawalników IWE w Politechnice Szczecińskiej, jak również organizację szkolenia i program ramowy studiów i kursu IWE. Dyplom IWE uczestnicy studiów podyplomowych uzyskują w ramach porozumienia pomiędzy Politechniką Szczecińską a Instytutem Spawalnictwa ANB. Przedstawiono kadrę dydaktyczną i wyposażenie laboratoryjne jakie oferuje Szczeciński Ośrodek swoim uczestnikom, przyszłym Międzynarodowym Inżynierom Spawalnikom.
EN
The article describes a centre for education and certification of international welding engineers (IWE) as well as organization and the syllabus of the IWE course at Szczecin Technical University. The course participants receive an IWE diploma as a part of an agreement between Szczecin Technical University and Instytut Spawalnictwa ANB. The publication presents teaching personnel and laboratory equipment of the centre offered to the future International Welding Engineers.
18
Struktura i właściwości mechaniczne domieszkowanych cementów kostnych
Nowacki J., Sajek A.
Inżynieria Materiałowa
|
2003
|
R. XXIV, nr 6
659-662
PL
W artykule opisano wpływ domieszki wodnego roztworu kalcytoniny łososiowej (Calcitonin 100) na właściwości mechaniczne i zmiany strukturalne akrylowego cementu kostnego Surgical Simplex (R) P. W celu opisania powyższej zależności zastosowano statyczną próbę ściskania i próbę zginania. Próby były przeprowadzone dla próbek w zakresie zawartości domieszki 0/10 ml, w temperaturach 20/40 stopni Celsjusza i przy szybkości odkształcenia 2/10 mm/min. Do ustalenia wpływu poszczególnych warunków prób wytrzymałościowych na otrzymane wyniki posłużono się metodami statycznymi wyznaczając odpowiednie modele. Zmiany strukturalne wywołane domieszką preparatu określono analizując zdjęcia powierzchni przełomów zginanych próbek. Zdjęcia wykonano metodą elektronowej mikroskopii skaningowej. Wyniki badań ukazują spadek właściwości mechanicznych kompozycji wraz ze zwiększaniem się domieszki preparatu, czego powodem jest zwiększenie liczby porów, w których lokalizuje się roztwór.
EN
The aim of this study was to determine the mechanical properties of acrylic bone cement (Surgical Simplex (R) P) modified by salmon calcitonin water solution (Calcitonin 100). The three-point bending test was used to measure the flexural strength and flexural modulus of cement, and the compression tests were used to measure the compression strength and modulus. The measurements have been made over a range of solution addition 0/10 ml, temperatures 20/40 degrees centigrade and strain rate 2/10 mm/min. Mathematical models were applied to experimental dissolution data revealing dependence of the mechanical tests conditions. One test specimen for each group was examined by a scanning electron microscope (SEM) to determine the microstructure modification and distribution of Calcitonin 100 in the structure. The results suggested that the bone cement modification decreases mechanical properties.
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