Different Types Of Ceramics Research Articles

Combined studies on glazed ceramic bodies from the Middle and Neo-Elamite periods (1500–539 BCE)

The Elamites have assigned specialized names for different types of ceramics, signaling a specialized approach to ceramic production during the Middle and Neo-Elamite periods. They were pioneers in the use of glazed ceramics on the Iranian Plateau. This investigation focuses on the examination of 29 samples of glazed ceramic bodies originating from the Middle-Elamite (~ 1500–1100 BCE) and Neo-Elamite periods (~ 1100–539 BCE). The objective of this analysis, centered on the earliest instances of glazed ceramic bodies in Iran, is to obtain a comparative examination of the ceramic bodies. Such an approach can be useful for understanding the diverse production techniques used by Elamites in the Middle-Elamite and Neo-Elamite periods. To achieve this purpose, X-ray diffraction and petrography was used to determine the mineralogical characteristics of the ceramic bodies. Further insight into the chemical analysis of the samples was obtained through Electron Probe Micro-Analysis. The experimental data allowed the classification of the samples into four distinct groups. Particularly noteworthy in this categorization is the diversity observed in the Neo-Elamite samples. This diversity of Neo-Elamite ceramic bodies can be attributed to two primary factors. Firstly, the Neo-Elamite period witnessed a more varied array of techniques for producing glazed ceramic bodies compared to the Middle-Elamite period. Unlike the Middle-Elamite glazed ceramics, which were solely utilized for architectural decoration (glazed bricks) and were locally produced, the Neo-Elamite period marked the first instance of glazed ceramic vessels being used in the southwest of Iranian plateau, leading to a higher technological diversity. Secondly, the frequency of trade and importation of glazed ceramics from other regions to the southwest of Iran was notably higher during the Neo-Elamite period compared to the Middle-Elamite one. A notable distinction emerges in the Middle-Elam period, where exclusively quartz-based ceramic bodies were referenced, setting it apart from other sample types.

Can a Self-etching Primer be Effective in Bonding Aligner Attachments to Different Types of Ceramics?

This in vitro study aimed to evaluate the effectiveness of pretreatment with a self-etching primer for bonding aligner attachments to lithium disilicate (LD) and monolithic zirconia (MZ) ceramics. Forty ceramics, including LD (n=20) and MZ (n=20), were divided into four study groups according to the surface pretreatments: LD specimens pretreated with universal primer (Monobond Plus, MP) after hydrofluoric acid etching (Group 1); MZ ceramics pretreated with MP after sandblasting (Group 2); LD ceramics pretreated with self-etching ceramic primer (Monobond etch & prime, MEP) (Group 3); and MZ ceramics pretreated with MEP after sandblasting (Group 4). The aligner composite (GC Aligner Connect) and universal adhesive (GPremio Bond) were used to prepare the resin attachments. The bond strength was evaluated by micro-shear bond strength (SBS) testing (0.1 mm/min) after thermocycling, and the remnant adhesive was scored according to the resin attachment remnant index (RARI). The SBS data were analyzed using ANOVA and Tukey tests, and the RARI scores were analyzed using the chi-square test. Group 1 had the lowest SBS, and group 2 had the highest SBS. There were significant differences between the groups in terms of bond strength (p<0.05). The RARI scores showed no significant differences, regardless of the pretreatment and ceramic type. The use of a self-etching primer increased the bond strength of resin attachments on LD ceramics. For zirconia ceramics, both ceramic primers are recommended for aligner attachment bonding.

Ngjitja e breketave ortodontike në siperfaqe të restaurimeve pro- tetike nga qeramika

The frequent demand for aesthetics in adults has resulted in dynamic changes in the methods and appliances with which orthodontic treatment is carried out, from braces welded to metal rings to clear aligners. With these new developments in technology and the continued demands of clinicians, advances were also made in bonding materi- als. Particularly challenging is the bonding of brackets to the surfaces of prosthetic restorations made of different types of ceramics, where their glass surface is not suitable for resin penetration, so there is a higher failure rate com- pared to bonding brackets to enamel. It mainly depends on the type of ceramic, the preparation of their surface, the bonding material, the type of brace and other factors. This review of the literature aims to analyze the factors that af- fect the shear bond strength (SBS) of orthodontic brack- ets attached to the surface of different types of ceramics used for prosthetic tooth restoration. Through this, we aim to contribute in determining a more appropriate way for bonding orthodontic brackets to the surfaces of ceramic prosthetic restorations.

Study of the Effect of Variation in the Phase Composition of ZrO2/MgO Ceramics on the Resistance to Radiation Damage during Irradiation with Kr15+ Ions

Interest in the modification of zirconium-containing ceramics is rooted in their great prospects for application as materials for creating inert matrices of dispersed nuclear fuel, which can replace traditional fuel containing uranium dioxide, as well as increase the degree of its burnup. Moreover, among the variety of different types of ceramics offered, zirconium dioxide is the most promising, since it has higher thermal conductivity values compared to other types of ceramics, as well as low volumetric thermal expansion. Moreover, the key limitations in the application of these types of ceramics as materials for creating inert matrices are polymorphic transformations, which have a negative impact on changes in the properties of ceramics under external influences. The evaluation results of the impact of change in the ZrO2 ceramics’ phase composition on the radiation damage resistance when subjected to irradiation with heavy ions, comparable in energy to fission fragments, are presented. The objects of study were samples of ZrO2 ceramics doped with MgO, the variation in the concentration of which leads to an acceleration of the processes of polymorphic transformations during thermal sintering, as well as the formation of a ZrO2/MgO-type structure with inclusions in the form of MgO grains. The results of the irradiation effect on the stability of the crystal structure of ceramics to deformation swelling due to the accumulation of deformation inclusions showed that ceramics with a monoclinic structure type are the least stable, for which, in the case of high irradiation fluences, the accumulation of deformation distortions leads to polymorphic transformations of the m—ZrO2 → t—ZrO2 type. During the evaluation of the irradiation effect on the change in mechanical properties and the softening degree, it was found that phase transformations of the m—ZrO2 → t—ZrO2 and t—ZrO2 → c—ZrO2 types lead to an increase in crack resistance by 1.5–2.0 times. Meanwhile, the formation of a structure of the ZrO2/MgO type with inclusions in the form of MgO grains in the interboundary space results in a softening resistance growth by over 7-fold. During tests for determining thermophysical parameters, as well as maintaining stability to crystal structure thermal expansion during prolonged thermal exposure, it was found that phase transformations associated with polymorphic transformations of the t—ZrO2 → c—ZrO2 type led to the preservation of the stability of thermophysical properties, even in the case of high irradiation fluences.

Experimental study on the effect of ceramic properties on failure behavior of composite armor

AbstractSeveral commonly used ceramics in ballistic protection were compared in terms of ballistic resistance and failure behavior, including alumina (Al2O3), silicon carbide (SiC), boron carbide (B4C), and silicon nitride (Si3N4). Hybrid ceramic ultrahigh molecular weight polyethylene composite armors were impacted by 12.7 mm armor‐piercing incendiary projectiles, with a velocity of around 490 m/s. Moreover, there was a layer of aramid fabric composite covering on the impacted side of the ceramic plate. These composite armors were paneled with four different types of ceramics as faceplates and had the same sizes. The ballistic test results show that B4C ceramic provides the worst protection performance, and SiC provides the best protection performance. The angles of ceramic cones formed by different ceramic plates under the same impact load are different, SiC is the widest and Al2O3 is the narrowest. Numerical simulation shows that several ceramic composite targets have the same resistance to the projectile at the pit stage. The fragment mass was quantified by using the screening method, and the results show that the Schumann distribution is more consistent with the experimental results.

Advanced and Functional Structured Ceramics: MgF2 and ZnS.

Due to difficulties in obtaining monomaterials, intensive research into the properties of ceramic compositions has been undertaken, along with developments to the properties of the compositions. These are not inferior to monomeric structures for a number of basic parameters. Among the different types of ceramics, magnesium fluoride and zinc sulfide occupy a special place due to their unique properties and specific applications. In this paper, we studied functional optoelectronics and modulating technique elements based on the advanced ceramics MgF2 and ZnS. The results of the transmittance spectral parameters and the contact angle estimation as well as an AFM analysis of the studied ceramics, both pure and structured with carbon nanotubes, are presented. We observed that the main characteristics of the studied materials with a surface modified by carbon nanotubes could be significantly changed when an innovative laser-oriented deposition method was applied. This method permitted the CNTs to be deposited in a vertical position on the material surface. The main features of the carbon nanotubes—such as the smaller value of the refractive index, the greater strength between the carbon atoms, and the effective surface—were taken into consideration. The analytical, quantum chemical, and experimental results of the studies of the changes in the basic physical parameters of the selected model of the inorganic matrices of the ceramics are given.

Curing through Ceramics: Influence of Different Light-Curing Units and Curing Modes on Bond Strength

Objectives: To measure and compare the bond strength between three different types of ceramics and resin cement, as well as the degree of conversion of resin cement after using different light-curing units and curing modes. Methods: Three types of ceramics—Leucite-reinforced (Empress CAD), Lithium disilicate (Emax CAD), and Zirconia (Emax ZirCAD)—of varying thicknesses (1.5 mm and 2.0 mm) were bonded to a light-cure resin cement (Variolink Esthetic LC). Light-curing was carried out using a monowave LCU (3M Elipar DeepCure-S LED Curing Light with irradiance of 1470 mW/cm2) and with polywave LCU (Ivoclar Bluephase PowerCure) using High, Turbo, and 3 s curing modes, respectively (1200, 2100, 3000 mW/cm2). A chevron-notch bond strength test (total n = 288) was conducted to calculate the fracture energy and interfacial bond strength (J/m2). The degree of cure (%DC) of the residual resin cement on debonded surfaces was measured using Fourier Transform Infrared Spectroscopy (FTIR). Collected data were statistically analysed under SPSS ver. 27 by conducting an ANOVA and Bonferroni post hoc test. The mode of failure was established using a scanning electron microscope (SEM). Results: A significant difference in interfacial bond strength was found between the three types of ceramic material groups (p &lt; 0.01). Cement cured through Empress that was 2 mm thick showed the highest bond strength (1.36 ± 0.46 J/m2), while the lowest was observed (0.26 ± 0.07 J/m2) in 2 mm Emax CAD using the 3 s mode. The use of different LCUs and curing modes had a significant influence on the %DC of resin cement seen in all groups, except 2 mm Emax ZirCAD. The dominant mode of failure for Empress, EmaxCAD, and EmaxZirCAD were cohesive, adhesive, and mixed, respectively. Conclusions: The type of ceramic and its thickness can significantly affect bond strength, and the results showed that polywave LCU is more effective than monowave LCU when curing through ceramics.

Ceramics, Glass and Glass-Ceramics for Personal Radiation Detectors.

Different types of ceramics and glass have been extensively investigated due to their application in brachytherapy, radiotherapy, nuclear medicine diagnosis, radioisotope power systems, radiation processing of food, geological and archaeological dating methods. This review collects the newest experimental results on the thermoluminescent (TL) properties of crystalline and glassy materials. The comparison of the physico-chemical properties shows that glassy materials could be a promising alternative for dosimetry purposes. Furthermore, the controlled process of crystallization can enhance the thermoluminescent properties of glasses. On the other hand, the article presents information on the ranges of the linear response to the dose of ionizing radiation and on the temperature positions of the thermoluminescent peaks depending on the doping concentration with rare-earth elements for crystalline and glassy materials. Additionally, the stability of dosimetric information storage (fading) and the optimal concentration of admixtures that cause the highest thermoluminescent response for a given type of the material are characterized. The influence of modifiers addition, i.e., rare-earth elements on the spectral properties of borate and phosphate glasses is described.

SiOC(N) Cellular Structures with Dense Struts by Integrating Fused Filament Fabrication 3D Printing with Polymer‐Derived Ceramics

Great advances have been made in various 3D printing methods for ceramics. Fabrication of Si‐based ceramics using polymer‐derived ceramics (PDCs) is gaining popularity. Using this route, preceramic polymers can be shaped in the polymer state and then pyrolyzed to produce different types of ceramics. Cellular ceramics can be manufactured using this technique. Herein, the novel fabrication of cellular ceramics with a two‐step process using PDCs is reported. First cellular structures are 3D printed with fused filament fabrication (FFF) using thermoplastic polyurethane and impregnated with preceramic polymer polysilazane. Second, pyrolysis of the impregnated structure produces a self‐similar ceramic cellular structure. The impact of 1) catalysts, 2) curing environment, and 3) pyrolysis sequence optimization to form cellular ceramics with fully dense SiOC(N) struts are systemically evaluated. The resultant custom ceramic components can tolerate operating temperatures of 1500 °C and can be manufactured for less than 5% of the cost of competing methods. The ceramic material is shown to be biocompatible and promotes fast cell adhesion. Finally, early‐stage cell activation on the SiOC(N) structure is shown to be tunable by adjusting the porosity with this 3D printing to mimic the bone tissue geometry for bone regeneration.

Effect of photo-polymerization mode on the degree of conversion of resin cement under different ceramic materials.

BACKGROUND This study evaluated the effect of different polymerization modes and duration on the degree of conversion (DC) of resin cement under different types of ceramics. METHODS Ceramic materials were divided into 3 groups (n=60): Group 1; CERASMART, Group 2; Vita Enamic and Group 3; Vita MARK II. Each group was then divided into three subgroups (n=20) according to the polymerization mode (A; low-intensity, B; high-intensity, and C; soft-start). Subgroups were then divided into two further groups according to the polymerization time (I; 10 s and II; 20 s). DC of light-cured resin cement beneath different kinds of ceramics was tested using FTIR spectroscopy. Results were compared to a control group cured without overlying ceramic. RESULTS While the type of ceramic and mode of polymerization showed a significant effect on the DC of resin cement, polymerization duration did not. Vita Mark II group showed significantly the highest DC of resin cement, followed by Vita Enamic and Cerasmart. High and low intensity polymerization modes did not show significant difference but both showed significantly lower DC when compared to soft start mode. CONCLUSIONS Type of ceramic and polymerization mode showed a direct effect on the DC of resin cement.

Shear bond strength of three CAD/CAM ceramics treated by Nd:YAG laser and HF

The main purpose of this study is to evaluate the influence of different types of ceramics and surface treatment methods on the shear bonding strength(SBS). Three different CAD/CAM ceramics were divided into 4 groups, respectively according to the following surface treatments: no treatment; etching with 4.5% HF acid; Nd:YAG laser irradiation; Nd:YAG laser followed by HF acid etching and then a silane-coupling agent and resin cement (Variolink N) were applied to each block. All specimens were stored in water for 24 h. Surface morphology of each specimen was evaluated and the SBS value was measured. The data were statistically analyzed by two-way ANOVA and LSD’s multiple comparison test (p < 0.05). Among Celtra Duo, highest SBS values were obtained in NY groups (14.80 MPa), followed by NY + HF group and HF group; the significantly highest SBS values of IPS Empress CAD specimens were obtained in HF group (13.54 MPa) (p < 0.05) and the remaining groups were not observed significant differences (p > 0.05). Among IPS e.max CAD, the HF group (14.70 MPa) showed the highest bond strength, followed by NY + HF and NY groups. There were no significant differences between NY and NY + HF group (p > 0.05). Nd:YAG laser irradiation significantly improved the surface of Celtra Duo and IPS e.max materials, but this setting of Nd:YAG laser was not appropriate for IPS Empress CAD.

Enhanced bonding strength of Al2O3/AlN ceramics joined via glass frit with gradient thermal expansion coefficient

Ceramics joining has been widely applied in MEMS sensors, microwave and imaging devices as well as other ceramic packaging applications to fabricate multifunctional ceramic components. In this study, a glass frit with gradient thermal expansion coefficient (TEC) has been applied as the bonding material to join the ceramic of Al2O3 and AlN. This glass frit consists of two types of glasses with different TEC. The Al2O3 and AlN ceramics have been successfully joined with this glass frit in muffle furnace at 850 °C for 1 h. The bonding strength of Al2O3/AlN ceramic joined via this glass frit exceeds 40 MPa without any cracks in the joining interface, which is much superior compared with that of conventional glass frit bonding. Our work demonstrates that the gradient-TEC glass frit bonding is an effective method to join different types of ceramics.

EFFECT OF TWO DIFFERENT SURFACE TREATMENTS ON MICRO-SHEAR BOND STRENGTH OF CAD/CAM AND HEAT PRESSED GLASS CERAMICS

Objective: The aim of this study was to evaluate the micro-shear bond strength between a dual cured resin cement and five different types of ceramics in composition and techniques of construction, using two different surface treatments.Materials & methods: A total of 50 ceramic disks were made and divided into 5 equal groups according to material type IPS Empress CAD, IPS e.max Press, IPS e.max CAD, Vita Suprinity and PM9 (n = 10). Each group was subdivided into 2 subgroups according to surface treatment they will be subjected to (n=5). Subgroup I: Bonding surfaces were etched with 5% HF acid, then coated with Monobond S. Subgroup II: Monobond Etch & Prime was applied on the bonding surfaces. For standardization of bonding surface area, 5 plastic tubings distributed on the bonding surface of each disk were used to place the dual resin cement. The samples were then subjected to micro-shear bond strength.Results: Results showed insignificant difference in micro-shear mean values between the IPS Empress CAD subgroups while significant differences were found between the other subgroups within the same group. Monobond Etch & Prime surface treatment resulted in higher micro-shear bond strength compared with HF surface treated subgroups for all the tested materials except for the PM9 and IPS e.max CAD. Conclusions: It was found that ceramic microstructure as well as the fabrication technique affects the selection surface treatment type. Also, Monobod Etch and Prime as a single step surface treatment produced clinically accepted and comparable results to that of HF treatment.

Comparison of translucency for different thicknesses of recent types of esthetic zirconia ceramics versus conventional ceramics … (in vitro study)

PurposeTo compare the translucency of 6 different types of ceramic material using three different thicknesses. Materials and methodsSquare shaped specimens were cut from different types of ceramics with variable translucencies (e.max CAD HT, e.max CAD LT, ultra-translucency zirconia, top-translucency zirconia, super-translucency zirconia and high-translucency zirconia). Total samples of 144 specimens were divided into 6 main groups according to material; each group was divided into 3 subgroups according to thickness used (0.4, 0.6 and 1 mm). Using spectrophotometer each specimen was tested three times against white and black background and the average was taken to calculate translucency parameter (TP). ResultsViewing the mean of translucency between studied groups, group EMHT (9.10 ± 1.45) scored the highest TP followed by group EMLT (8.36 ± 1.42) then group UTZ (6.66 ± 2.49), TTZ (6.25 ± 0.95), STZ (4.93 ± 0.96) and HTZ (4.83 ± 1.34) showed the lowest value. Each material showed a difference in mean value with different thicknesses. At 0.4 mm thickness one-way ANOVA revealed no significant difference between EMHT and UTZ (P = 0.942). ConclusionsGlass ceramics showed higher TP values than crystalline based ceramics which means e.max is more translucent than zirconia. The thickness of the material has direct effect on its translucency. Ultra-translucency zirconia is the most recommended material to be used in conservative esthetic cases.

Investigation of the mechanical properties on the large amplitude free vibrations of the functionally graded material sandwich plates

In this paper, the geometrically nonlinear formulation based on von Karman’s assumptions is employed to study the large amplitude free vibrations of functionally graded materials sandwich plates. The functionally graded material sandwich plate is made up of two layers of power-law functionally graded material face sheet and one layer of ceramic homogeneous core. A hierarchical finite element is employed to define the model, taking into account the effects of the transverse shear deformation and the rotatory inertia. The equations of motion for the nonlinear vibration of the functionally graded material sandwich plates are obtained using Lagrange’s equations. Employing the harmonic balance method, the equations of motion are converted from time domain to frequency domain and then solved iteratively using the linearized updated mode method. Results for linear and nonlinear frequency parameters of the simply supported functionally graded material sandwich plates are computed and compared with the published values, and an excellent agreement was found. The influence of the mechanical properties of the functionally graded material, thickness ratio of FGM layers, and volume fraction exponent on the backbone curves and on the nonlinear frequency parameters are investigated. The effects of the material properties of two different types of ceramics on the large amplitude vibration behaviors of the functionally graded material sandwich plates is also presented and discussed for the first time.

P.1.c.018 Prevalence of gastrointestinal symptoms in young people with autism spectrum disorder

To compare the translucency of 6 different types of ceramic material using three different thicknesses.Square shaped specimens were cut from different types of ceramics with variable translucencies (e.max CAD HT, e.max CAD LT, ultra-translucency zirconia, top-translucency zirconia, super-translucency zirconia and high-translucency zirconia). Total samples of 144 specimens were divided into 6 main groups according to material; each group was divided into 3 subgroups according to thickness used (0.4, 0.6 and 1 mm). Using spectrophotometer each specimen was tested three times against white and black background and the average was taken to calculate translucency parameter (TP).Viewing the mean of translucency between studied groups, group EMHT (9.10 ± 1.45) scored the highest TP followed by group EMLT (8.36 ± 1.42) then group UTZ (6.66 ± 2.49), TTZ (6.25 ± 0.95), STZ (4.93 ± 0.96) and HTZ (4.83 ± 1.34) showed the lowest value. Each material showed a difference in mean value with different thicknesses. At 0.4 mm thickness one-way ANOVA revealed no significant difference between EMHT and UTZ (P = 0.942).Glass ceramics showed higher TP values than crystalline based ceramics which means e.max is more translucent than zirconia. The thickness of the material has direct effect on its translucency. Ultra-translucency zirconia is the most recommended material to be used in conservative esthetic cases.

Ceramic fabrication using Mask-Image-Projection-based Stereolithography integrated with tape-casting

Ceramic components with complex geometry are difficult to fabricate. Layer-based additive manufacturing processes such as ceramic-suspension-based stereolithography (SL) provide a direct way of fabricating ceramic components from computer-aided design (CAD) models. In such an SL process, fine ceramic powders are mixed with liquid photocurable resin into ceramic suspension. The suspension-based slurry is then used in the SL process to fabricate green parts with desired shapes. A sintering process is further required to convert the green parts into dense ceramic components. In this paper, several key challenges of the ceramic-suspension-based SL process are discussed including the recoating and curing ceramic suspension with high solid loading. A novel Mask-Image-Projection-based Stereolithography (MIP-SL) process by integrating ceramic tape-casting and bottom-up projection methods is presented for fabricating dense ceramic components from CAD models. Various approaches to increase the solid loading in green parts are discussed including suspension preparation, image projection, layer recoating and separation. A prototype system based on the presented ceramics fabrication process has been developed. Test cases of different types of ceramics are presented to demonstrate the effectiveness of the presented fabrication method. The post-processing of green parts to convert them into dense ceramic components is also discussed with some sintering results presented.

Additive manufacturing of ceramics: A review

Additive manufacturing (AM) of ceramics is coming to an aera where the first industrial applications are becoming economically profitable. This review paper provides a survey of AMmethods reported in literature to shape ceramic components. It demonstrates that AM has produced ceramic parts that have no cracks or large pores and have mechanical properties close to those of conventionally produced ceramics. Crackand pore-free ceramics can be manufacturedbyoptimizing theAMprocess parameters orperforming extradensification steps after theAMprocess. It is also advisable to incorporate colloidal processing techniques in the AM process. Finally, the paper demonstrates that, especially forAMof ceramics, themulti-step indirectAMprocesses aremore appropriate to shape different types of ceramics, while the single-step direct AM processes can produce ceramic parts more rapidly.

New Ecological Lubricants on the Basis of Lyotropic Liquid Crystals Formed by Solutions of Maracuja Oil Ethoxylate

Aqueous 60% solutions of maracuja oil ethoxylated with 60 mol of ethylene oxide containing hexagonal mesophases were proposed as model biocompatible safe-to-use lubricants. Tests were carried out at steady loads using a four-ball tester (Tester T-02) (1–6 kN) and a ball-on-disk tribometer (Tester T-11) (10–50 N) in order to verify tribological properties of the solutions. At high loads (Tester T-02) a significant, almost 4.5-fold reduction in the coefficients of friction (μ) and about 2.5-fold decrease in wear scar diameter (d) were found relative to water as a base. Tester T-11 was used to study the suitability of the lubricant tested for lubrication of the following friction pairs: steel ball–steel disk, different types of ceramics, and polymers at lower loads. The ethoxylate solutions are excellent lubricants also for those pairs of materials. The interpretation of the results obtained was based on the proposed adsorptive-structural mechanism.

MACHINING OF HARD-WORKABLE MATERIALS USING TWO LASER BEAMS

The paper gives an overview of the importance of modern materials in industry and problems regarding their machining. Materials such as: composites, hard metals, different types of ceramics and similar are hard to machine using conventional methods, because of their nature and mechanical properties. One of the ways to solve the machining problem for this type of material is by using a laser beam machining with two beams. In this process each laser beam makes a groove on the working area while the volume of the material lying between the crossover of two beams is eliminated. Theoretical discussion on thermal properties of materials which were subject to laser machining created a mathematical model which was subsequently compared with the experimental results.