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Nowadays, improvement of the surface finish of parts manufactured by fused deposition modelling is a well-studied topic. Chemical post-treatments have proven to be the best technique in terms of time consumption and smoothness improvement. However, these treatments modify the structure of the material and, consequently, its mechanical properties. This relationship was studied in this work. In this case, on the basis of a previous study on crystallisation, polylactic acid pieces were subjected to different post-treatments to evaluate their effects on the sample’s mechanical properties, i.e., tensile strength and hardness. Models were obtained according to their percentage of crystallisation, which was related to the different treatments, as well as immersion time. Dramatic changes were obtained within a wide range of material behaviour with some treatments. Specifically, changes were obtained in the maximum stress (from 55 to 20 MPa), in elongation (from 3% to 260%), and in the hardness scale (Shore D to A).

Nowadays, improvement of the surface finish of parts manufactured by fused deposition modelling is a well-studied topic. Chemical post-treatments have proven to be the best technique in terms of time consumption and smoothness improvement. However, these treatments modify the structure of the material and, consequently, its mechanical properties. This relationship was studied in this work. In this case, on the basis of a previous study on crystallisation, polylactic acid pieces were subjected to different post-treatments to evaluate their effects on the sample’s mechanical properties, i.e., tensile strength and hardness. Models were obtained according to their percentage of crystallisation, which was related to the different treatments, as well as immersion time. Dramatic changes were obtained within a wide range of material behaviour with some treatments. Specifically, changes were obtained in the maximum stress (from 55 to 20 MPa), in elongation (from 3% to 260%), and in the hardness scale (Shore D to A).

Nowadays, improvement of the surface finish of parts manufactured by fused deposition modelling is a well-studied topic. Chemical post-treatments have proven to be the best technique in terms of time consumption and smoothness improvement. However, these treatments modify the structure of the material and, consequently, its mechanical properties. This relationship was studied in this work. In this case, on the basis of a previous study on crystallisation, polylactic acid pieces were subjected to different post-treatments to evaluate their effects on the sample’s mechanical properties, i.e., tensile strength and hardness. Models were obtained according to their percentage of crystallisation, which was related to the different treatments, as well as immersion time. Dramatic changes were obtained within a wide range of material behaviour with some treatments. Specifically, changes were obtained in the maximum stress (from 55 to 20 MPa), in elongation (from 3% to 260%), and in the hardness scale (Shore D to A).

In this paper, the phenomenon of intergranular fracture in polycrystalline materials is investigated using a nonlinear fracture mechanics approach. The nonlocal cohesive zone model (CZM) for finite thickness interfaces recently proposed by the present authors is used to describe the phenomenon of grain boundary separation. From the modelling point of view, considering the dependency of the grain boundary thickness on the grain size observed in polycrystals, a distribution of interface thicknesses is obtained. Since the shape and the parameters of the nonlocal CZM depend on the interface thickness, a distribution of interface fracture energies is obtained as a consequence of the randomness of the material microstructure. Using these data, fracture mechanics simulations are performed and the homogenized stress-strain curves of 2D representative volume elements (RVEs) are computed. Failure is the result of a diffuse microcrack pattern leading to a main macroscopic crack after coalescence, in good agreement with the experimental observation. Finally, testing microstructures characterized by different average grain sizes, the computed peak stresses are found to be dependent on the grain size, in agreement with the trend expected according to the Hall-Petch law.

In this paper, the phenomenon of intergranular fracture in polycrystalline materials is investigated using a nonlinear fracture mechanics approach. The nonlocal cohesive zone model (CZM) for finite thickness interfaces recently proposed by the present authors is used to describe the phenomenon of grain boundary separation. From the modelling point of view, considering the dependency of the grain boundary thickness on the grain size observed in polycrystals, a distribution of interface thicknesses is obtained. Since the shape and the parameters of the nonlocal CZM depend on the interface thickness, a distribution of interface fracture energies is obtained as a consequence of the randomness of the material microstructure. Using these data, fracture mechanics simulations are performed and the homogenized stress-strain curves of 2D representative volume elements (RVEs) are computed. Failure is the result of a diffuse microcrack pattern leading to a main macroscopic crack after coalescence, in good agreement with the experimental observation. Finally, testing microstructures characterized by different average grain sizes, the computed peak stresses are found to be dependent on the grain size, in agreement with the trend expected according to the Hall-Petch law.

The thickness distribution and defect density of illite crystallites (both illite–smectite and illite–muscovite phases) and chlorite are presented for a set of clay-mineral crystallinity-index standards, as determined by TEM and XRD methods for both the whole rock and disaggregated clay-sized fractions. The pelitic standards, selected from the Variscan rocks of southwestern England, display the full array of typical microstructural transformations that characterize the prograde transition from diagenesis (zeolite facies) to epizonal (greenschist facies), with increasing thickness of crystallites and decreasing concentration of lattice imperfections. Crystallite thickness, measured from TEM lattice-fringe images in the c* direction of both illite and chlorite, commonly deviate from lognormal distributions, with positive skewness toward small sizes. These distributions are considered to reflect complex histories of nucleation and growth, as well as structural modifications due to rock strain. Crystal damage caused by rock disaggregation, in the form of splitting along crystallite boundaries and other planar defects, can be observed in all clay-sized separates. The degree of damage increases as a function of increasing size of crystals, and clearly enhances the differences in mean thickness of the crystallites between the whole rock and clay-sized fractions, particularly in anchizonal and epizonal slates. Although clay separates yield smaller mean thicknesses of crystallites and show thickness distributions with lower degrees of skewness and standard deviation than measured from matrix of the pelitic rocks, the aaa and bbb2 shape parameters (the mean and variance of the natural logarithms of the sizes) for both grain-size fractions define a common crystal-growth path when plotted in aaa – bbb2 space. This feature shows that ultrasonic disaggregation has not modified the shape of the thickness distributions in a way that has influenced the interpretation of the mechanis

Tato práce se zabývá výzkumem a popisem dekarbonatačního procesu vápence při výpalu vápna. Cílem práce je pokusit se najít souvislost mezi vlastnostmi vstupní suroviny a průběhem procesu dekarbonatace, který je sledován pomocí vysokoteplotní XRD analýzy. V experimentální části bude vyhodnocena mikrostruktura vznikajícího oxidu vápenatého, a to zejména z pohledu velikosti krystalitů., The bachelor thesis deals with a research and a description of decarbonation process of limestone during the lime burning. The goal of the bachelor thesis is to try to find a connection between characteristics of input material and course of the decarbonation process, which is monitored by high temperature XRD analysis. There is an evaluation of the microstructure of emerging calcium oxide, especially by the size of the crystallites, in the experimental part.

Tato práce se zabývá výzkumem a popisem dekarbonatačního procesu vápence při výpalu vápna. Cílem práce je pokusit se najít souvislost mezi vlastnostmi vstupní suroviny a průběhem procesu dekarbonatace, který je sledován pomocí vysokoteplotní XRD analýzy. V experimentální části bude vyhodnocena mikrostruktura vznikajícího oxidu vápenatého, a to zejména z pohledu velikosti krystalitů., The bachelor thesis deals with a research and a description of decarbonation process of limestone during the lime burning. The goal of the bachelor thesis is to try to find a connection between characteristics of input material and course of the decarbonation process, which is monitored by high temperature XRD analysis. There is an evaluation of the microstructure of emerging calcium oxide, especially by the size of the crystallites, in the experimental part.

Práce je součástí grantového zadání a zabývá se vlivem vstupní suroviny, tedy vápence, na reaktivitu a rychlost dekarbonatace. Cílem práce je zjistit, jaký vliv a vztah má chemické složení, petrografie, geneze a diageneze, porozita a mikrostruktura vápenců na reaktivitu a rychlost a průběh dekarbonatace. Předmětem experimentální části potom je vyhodnocení analýz provedených na vzorcích vápenců, jako je porozita, reaktivita zjištěná metodou Bischof – Uhde a proces dekarbonatace kalcitu z pohledu krystalinity produktu., This thesis is a part of grant assignment and focuses on the effect and properties of input material, limestone, on reactivity and speed of decarbonation. The aim of this thesis is to find the effect of chemical composition, petrography, genesis and diagenesis, porosity and microstructure of limestones on reactivity and speed and profile of decarbonation. The experimental part of thesis describes analysis of chosen limestone samples regarding porosity, reactivity by Bischof-Uhde method and process of decarbonation of calcite in term of crystallinity of product.

Předkládaná diplomová práce se zabývá výzkumem souvislostí mezi typem vápence a procesem dekarbonatace. V teoretické části jsou popsány typy vápenců a geneze vápenců, dále proces dekarbonatace, metody využívané pro analýzu struktury vápenců a výzkumy v řešené problematice. V experimentální části jsou na souboru vybraných vzorků vápenců provedeny HT-XRD analýza, SEM analýza a simultánní TG/DTA analýza. Pomocí získaných dat je sledován proces dekarbonatace vápence a změna mikrostruktury vznikajícího oxidu vápenatého., Submitted master´s thesis examines research of connections between the type of limestone and the process of decarbonation. Types of limestones and genesis of limestones are described in the theoretical part of the thesis, followed by the description of the process of decarbonation, methods used for analysis of limestone structure and research of solved problems. Experimental part of the thesis describes HT-XRD analysis, SEM analysis and simultaneous TG/DTA analysis performed on chosen group of limestone samples. The process of decarbonation and the change of microstructure of the developing calcium oxide are examined from the obtained data.

Předkládaná diplomová práce se zabývá výzkumem souvislostí mezi typem vápence a procesem dekarbonatace. V teoretické části jsou popsány typy vápenců a geneze vápenců, dále proces dekarbonatace, metody využívané pro analýzu struktury vápenců a výzkumy v řešené problematice. V experimentální části jsou na souboru vybraných vzorků vápenců provedeny HT-XRD analýza, SEM analýza a simultánní TG/DTA analýza. Pomocí získaných dat je sledován proces dekarbonatace vápence a změna mikrostruktury vznikajícího oxidu vápenatého., Submitted master´s thesis examines research of connections between the type of limestone and the process of decarbonation. Types of limestones and genesis of limestones are described in the theoretical part of the thesis, followed by the description of the process of decarbonation, methods used for analysis of limestone structure and research of solved problems. Experimental part of the thesis describes HT-XRD analysis, SEM analysis and simultaneous TG/DTA analysis performed on chosen group of limestone samples. The process of decarbonation and the change of microstructure of the developing calcium oxide are examined from the obtained data.

Práce je součástí grantového zadání a zabývá se vlivem vstupní suroviny, tedy vápence, na reaktivitu a rychlost dekarbonatace. Cílem práce je zjistit, jaký vliv a vztah má chemické složení, petrografie, geneze a diageneze, porozita a mikrostruktura vápenců na reaktivitu a rychlost a průběh dekarbonatace. Předmětem experimentální části potom je vyhodnocení analýz provedených na vzorcích vápenců, jako je porozita, reaktivita zjištěná metodou Bischof – Uhde a proces dekarbonatace kalcitu z pohledu krystalinity produktu., This thesis is a part of grant assignment and focuses on the effect and properties of input material, limestone, on reactivity and speed of decarbonation. The aim of this thesis is to find the effect of chemical composition, petrography, genesis and diagenesis, porosity and microstructure of limestones on reactivity and speed and profile of decarbonation. The experimental part of thesis describes analysis of chosen limestone samples regarding porosity, reactivity by Bischof-Uhde method and process of decarbonation of calcite in term of crystallinity of product.

Tato práce se zabývá výzkumem a popisem dekarbonatačního procesu vápence při výpalu vápna. Cílem práce je pokusit se najít souvislost mezi vlastnostmi vstupní suroviny a průběhem procesu dekarbonatace, který je sledován pomocí vysokoteplotní XRD analýzy. V experimentální části bude vyhodnocena mikrostruktura vznikajícího oxidu vápenatého, a to zejména z pohledu velikosti krystalitů., The bachelor thesis deals with a research and a description of decarbonation process of limestone during the lime burning. The goal of the bachelor thesis is to try to find a connection between characteristics of input material and course of the decarbonation process, which is monitored by high temperature XRD analysis. There is an evaluation of the microstructure of emerging calcium oxide, especially by the size of the crystallites, in the experimental part.

Práce je součástí grantového zadání a zabývá se vlivem vstupní suroviny, tedy vápence, na reaktivitu a rychlost dekarbonatace. Cílem práce je zjistit, jaký vliv a vztah má chemické složení, petrografie, geneze a diageneze, porozita a mikrostruktura vápenců na reaktivitu a rychlost a průběh dekarbonatace. Předmětem experimentální části potom je vyhodnocení analýz provedených na vzorcích vápenců, jako je porozita, reaktivita zjištěná metodou Bischof – Uhde a proces dekarbonatace kalcitu z pohledu krystalinity produktu., This thesis is a part of grant assignment and focuses on the effect and properties of input material, limestone, on reactivity and speed of decarbonation. The aim of this thesis is to find the effect of chemical composition, petrography, genesis and diagenesis, porosity and microstructure of limestones on reactivity and speed and profile of decarbonation. The experimental part of thesis describes analysis of chosen limestone samples regarding porosity, reactivity by Bischof-Uhde method and process of decarbonation of calcite in term of crystallinity of product.

Tato práce se zabývá výzkumem a popisem dekarbonatačního procesu vápence při výpalu vápna. Cílem práce je pokusit se najít souvislost mezi vlastnostmi vstupní suroviny a průběhem procesu dekarbonatace, který je sledován pomocí vysokoteplotní XRD analýzy. V experimentální části bude vyhodnocena mikrostruktura vznikajícího oxidu vápenatého, a to zejména z pohledu velikosti krystalitů., The bachelor thesis deals with a research and a description of decarbonation process of limestone during the lime burning. The goal of the bachelor thesis is to try to find a connection between characteristics of input material and course of the decarbonation process, which is monitored by high temperature XRD analysis. There is an evaluation of the microstructure of emerging calcium oxide, especially by the size of the crystallites, in the experimental part.

Předkládaná diplomová práce se zabývá výzkumem souvislostí mezi typem vápence a procesem dekarbonatace. V teoretické části jsou popsány typy vápenců a geneze vápenců, dále proces dekarbonatace, metody využívané pro analýzu struktury vápenců a výzkumy v řešené problematice. V experimentální části jsou na souboru vybraných vzorků vápenců provedeny HT-XRD analýza, SEM analýza a simultánní TG/DTA analýza. Pomocí získaných dat je sledován proces dekarbonatace vápence a změna mikrostruktury vznikajícího oxidu vápenatého., Submitted master´s thesis examines research of connections between the type of limestone and the process of decarbonation. Types of limestones and genesis of limestones are described in the theoretical part of the thesis, followed by the description of the process of decarbonation, methods used for analysis of limestone structure and research of solved problems. Experimental part of the thesis describes HT-XRD analysis, SEM analysis and simultaneous TG/DTA analysis performed on chosen group of limestone samples. The process of decarbonation and the change of microstructure of the developing calcium oxide are examined from the obtained data.

Práce je součástí grantového zadání a zabývá se vlivem vstupní suroviny, tedy vápence, na reaktivitu a rychlost dekarbonatace. Cílem práce je zjistit, jaký vliv a vztah má chemické složení, petrografie, geneze a diageneze, porozita a mikrostruktura vápenců na reaktivitu a rychlost a průběh dekarbonatace. Předmětem experimentální části potom je vyhodnocení analýz provedených na vzorcích vápenců, jako je porozita, reaktivita zjištěná metodou Bischof – Uhde a proces dekarbonatace kalcitu z pohledu krystalinity produktu., This thesis is a part of grant assignment and focuses on the effect and properties of input material, limestone, on reactivity and speed of decarbonation. The aim of this thesis is to find the effect of chemical composition, petrography, genesis and diagenesis, porosity and microstructure of limestones on reactivity and speed and profile of decarbonation. The experimental part of thesis describes analysis of chosen limestone samples regarding porosity, reactivity by Bischof-Uhde method and process of decarbonation of calcite in term of crystallinity of product.