Search results

This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the paper contains references to papers, conference proceedings and theses/dissertations on the subject that were published between 1977‐1998. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, ferrites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.

Ceramic materials and glasses have become important in modern industry as well as in the consumer environment. Heat resistant ceramics are used in the metal forming processes or as welding and brazing fixtures, etc. Ceramic materials are frequently used in industries where a wear and chemical resistance are required criteria (seals, liners, grinding wheels, machining tools, etc.). Electrical, magnetic and optical properties of ceramic materials are important in electrical and electronic industries where these materials are used as sensors and actuators, integrated circuits, piezoelectric transducers, ultrasonic devices, microwave devices, magnetic tapes, and in other applications. A significant amount of literature is available on the finite element modelling (FEM) of ceramics and glass. This paper gives a listing of these published papers and is a continuation of the author's bibliography entitled “Finite element modelling of ceramics and glass” and published in Engineering Computations, Vol. 16, 1999, pp. 510‐71 for the period 1977‐1998.

The form of the paper is a bibliography. Listed references have been retrieved from the author's database, MAKEBASE. Also Compendex has been checked. The period is 1998‐2004.

Provides a listing of 1,432 references. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.

This paper makes it easy for professionals working with the numerical methods with applications to ceramics and glasses to be up‐to‐date in an effective way.

The purpose of this paper is to report a study about the rapid prototyping method of dental glass‐ceramic restoration.

Dental glass‐ceramic restoration materials have excellent physical and chemical, mechanical, aesthetic and biocompatibility characteristics. However, casting methods adopted at present have complicated procedures and high costs; the forming qualities are especially difficult to control. These problems greatly restrict their clinical application and promotion. Therefore, a new forming process based on selective laser sintering (SLS) technology is proposed. First, dental glass‐ceramic is processed into fine powder through a special heat treatment process. Then, the dental restoration parts are manufactured using SLS without any moulds. In this paper, the effects of processing parameters including laser power, scan speed, scan spacing and preheating temperature on the relative density and mechanical properties of the sintered parts are studied.

The experimental results have shown that for the composite powder of epoxy resin binder E‐12 and K₂O‐Al₂O₃‐SiO₂ series of dental glass‐ceramics, when preheating temperature, layer thickness, laser power, scan speed and scan spacing are, respectively, 30∼35°C, 0.08 mm, 21 W, 1,800 mm/s and 0.10 mm/s, the relative densities of dental glass‐ceramic parts are relatively high; the mechanical properties and forming effect are excellent. The relative density and bending strength of SLS parts under the optimized processing parameters are 37.40 per cent and 2.08 MPa, respectively.

This study only concerns the preparation and SLS of the dental glass‐ceramic powders. Further investigations are planned to be conducted on post processing, such as binder decomposition, isostatic press and high temperature sintering.

This study will provide a theoretical and technical basis for dental glass‐ceramic restorations of SLS.

Lithium disilicate glass-ceramics (LS2 GC) are widely used as dental prosthetics and dental restorations. Based LS2 GC have hardness and translucency similar to that of natural teeth. This study aims to investigate the tribological features of LS2 GC with crystalline volume fraction of 64% and different crystal sizes from 8 µm to 34 µm for different counterparts.

The tribological behavior was investigated using a pin-on-disc tribometer with alumina and tungsten carbide (WC) spheres, applied load of 5 N and sliding speed of 5 cm/s at normal conditions. The coefficient of friction was measured continuously up to 10,000 sliding cycles. The specific wear rate was calculated from tribological and profile measurements. The wear mechanism was investigated by surface morphology analysis.

The coefficient of friction during running-in varied from 0.8 to 1.0 for the alumina counterpart, because of severe wear. Afterwards, it reduced and reached a stationary regime, characterized by a mild wear regime and the formation of a tribolayer formed by the debris. For the WC counterpart, the coefficient of friction curves increased initially with sliding cycles up to a stationary regime. The samples tested against WC presented the lowest specific wear rate (k), and no variation of wear rate with crystal size was observed. For samples tested against the alumina, crystallization and crystal size increased the wear resistance.

This study evaluated the effect of different counterfaces on the tribological properties of the LS2 GC, an important glass-ceramic base for many dental prosthetics and dental restorations, discussing results in light of the contact mechanics. Different specific wear rates, wear regimes and dependence on the glass-ceramic microstructure were observed depending on the counterpart.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2019-0352/

The Secretary of State after approving proposals submitted by the Ceramics, Glass and Mineral Products Industry Training Board for the imposition of a further levy on employers in the ceramics, glass and mineral products industry and in exercise of his powers under section 4 of the Industrial Training Act 1964 and of all other powers enabling him in that behalf hereby makes the following Order:—

This paper seeks to detail the fabrication of a glass‐ceramic substrate, based on the LiO₂‐ZrO₂‐SiO₂‐Al₂O₃ (LZSA) system, by laminated object manufacturing (LOM) using water‐based cast tapes.

Small amounts of ZrSiO₄ were added to control the thermal expansion coefficient (TEC) of the original glass‐ceramic (LZSA5Zr: LZSA+5 wt% ZrSiO₄). In order to verify the influence of the amount and nature of crystalline phases on the thermal and dielectric behavior of the material, LZSA and LZSA5Zr laminates were sintered at 700°C for 30 min and crystallized at either 800 or 850°C for 30 min.

LZSA laminates (sintered and crystallized at 700 and 800°C, respectively) exhibited a relative density of ∼90 percent, a dielectric constant of 8.39, a dielectric loss tangent of 0.031 and TEC of 5.5×10⁻⁶ K⁻¹ (25‐550°C). The addition of 5 wt% ZrSiO₄ to original LZSA glass‐ceramics led to a nearly constant TEC value of 6×10⁻⁶ K⁻¹ throughout the whole temperature interval (25‐800°C). Dielectric properties of LZSA5Zr did not show any remarkable change when compared to original LZSA.

The thermal, mechanical and electrical properties of LZSA glass‐ceramic laminates fabricated by LOM makes them potential candidates for substrate applications.

The Secretary of State after approving proposals submitted by the Ceramics, Glass and Mineral Products Industry Training Board for the imposition of a further levy on employers in the ceramics, glass and mineral products industry and in exercise of his powers under section 4 of the Industrial Training Act 1964 and of all other powers enabling him in that behalf hereby makes the following Order:—

This paper presents the results of an investigation into alternative substrate materials to alumina and the associated techniques necessary to utilise them in microwave integrated circuits (MICs). The major driving force for this work was to reduce MIC processing costs without significantly degrading the RF performance. Different glass ceramic systems were assessed and 6–18 GHz gain modules were produced on the most promising of these materials. One glass ceramic material, CMA6, with a dielectric content of 6 • 4, showed a comparable measured gain to that obtained for alumina circuits between 6 and 15 GHz. Cost analysis indicated that, with the reductions in material costs and yield improvements on using glass ceramic substrates, a cost saving of approximately 12% per module is feasible.

The Secretary of State after approving proposals submitted by the Ceramics, Glass and Mineral Products Industry Training Board for the imposition of a further levy on employers in the ceramics, glass and mineral products industry and in exercise of powers conferred by section 4 of the Industrial Training Act 1964 and now vested in him, and of all other powers enabling him in that behalf hereby makes the following Order:—

The Minister of Labour after approving proposals submitted by the Ceramics, Glass and Mineral Products Industry Training Board for the imposition of a levy on employers in the ceramics, glass and mineral products industry and by virtue of the powers conferred on him by section 4 of the Industrial Training Act 1964 and of all other powers enabling him in that behalf hereby makes the following Order:—