Ljerka Slokar Benić

University of Zagreb Faculty of Metallurgy · Department of Physical Metallurgy

In order to improve the hold and function of dentures for the patient, various prostheses made of metal, mostly metal alloys, are used every day in dental practise. Cobalt-chromium alloys are usually the first choice because they have very good mechanical properties and satisfactory clinical conditions. Nowadays, laser welding is increasingly used...

Due to their good mechanical and other properties, cobalt-chromium alloys (Co-Cr) are often used in prosthetic therapy. The metal structures of prosthetic works can be damaged and break, and depending on the extent of the damage, they can be re-joined. Tungsten inert gas welding (TIG) produces a high-quality weld with a composition very close to th...

Cobalt–chromium alloys (Co-Cr) are widely used in dentistry due to their excellent mechanical properties and corrosion resistance. Since prosthetic materials must be permanently stable in the oral cavity, it is very important to determine the release of ions from alloys in the oral cavity. In dentistry today, metals and alloys are mainly joined by...

Lithium disilicate and zirconia are the two most popular materials for aesthetic and dental prosthetic work; however, due to their limitations, a new material is being researched, namely zirconia-reinforced lithium disilicate, the surface of which is treated with different procedures to achieve the best possible surface properties. In this study, t...

This paper deals with production of hard metal by powder metallurgy and its effect on the environment. Hard metal is a composite material that consists of tungsten carbide as the hard refractory phase and cobalt or nickel as the soft metal binder phase. It cannot be produced by classical casting technology. Owing to its excellent properties, such a...

The influence of boron carbide and tungsten carbide on the apparent porosity, density, coercive force, hardness and microstructure of metal matrix composite of the Ferro-TiC type, is presented in this paper. The samples of investigated steel/titanium carbide composite were produced by powder metallurgy process, i.e. by powders mixing and compacting...

In this paper, thermomechanical processing of niobium microalloyed steel was performed with the purpose of determining the interaction between niobium precipitates and dislocations, as well as determining the influence of the temperature of final deformation on the degree of precipitation and dislocation density. Two variants of thermomechanical pr...

Due to good properties, which meet the requirements for use as biomaterials, titanium and titanium alloys have been increasingly used as dental implants. Until recently, dental titanium alloys were produced by casting. Since this process does not meet the terms of economy and efficiency, the production of titanium implants by powder metallurgy are...

Dentistry as a branch of medicine has an important role in the health of the human, while applying new technologies the maintaining of oral health is much more effective. For that purpose many dental products are used, such as crowns, bridges, implants, which are made of various metallic materials the mostly by casting or forging. They have to poss...

This paper deals with the waste foundry molding sand which originally comes from the casting production. Adsorption of Cu (II) ions on the waste foundry molding sand was studied. Experimental data were processed using adsorption isotherms. Obtained results show that the experimental data are best described by the Langmuir isotherm. The following ad...

This study presents the results of light optical and scanning electron microscopy as well as energy dispersive spectroscopy investigation of the Ni-based self-fluxing alloys (NiCrBSi, NiCrWBSi and NiCrBSi + WC) deposited on steel substrates (heat treated carbon steel C45, heat treated low-alloyed steel 42CrMo4 and austenitic stainless steel X6CrNiM...

Metallic glass Zr 53 Cu 40 Al 7 was prepared in the form of ribbon by melt-spinning the master alloy in a purified argon atmosphere at a lower quenching rate. Its thickness of 0.1 mm is near limit of bulk glasses. Presence of crystallites in the amorphous matrix was confirmed by X-ray diffraction (XRD). Homogeneity and chemical composition were inv...

This paper presents the results of an experimental and numerical investigation of the tensile behaviour of glass fibre reinforced epoxy composite for incremental and cyclic creep-recovery load conditions. The proposed constitutive model incorporates linear viscoelasticity coupled with damage and viscoplasticity for prediction of the creep-recovery...

Titanium and its alloys are promising materials in dentistry because they have good biocompatibility, corrosion resistance and physical and mechanical properties. For that reason, they have many applications as crowns, inlays, bridges, dental implants etc. Titanium can be alloyed with other metals, such as chromium and niobium, to modify its mechan...

The examination of a series of as-cast Ti-Cr-Co alloys was performed with the purpose of obtaining new β-type Ti-alloys. Experimental results revealed that the alloys, containing 10-20 atomic percent Cr and 5 atomic percent Co, were single β-phase alloys. They displayed hardness values in the order of 359 to 423 HV, high compressive strength (1620-...

The aim of this work is to investigate the influence of chemical treatment by inorganic acids (H2SO4 and HNO3) as oxidizing agents on the surface properties of carbon black. The specific surface area, average pore diameter, total pore volume were analyzed by Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods. Fourier transform in...

Titanium and its alloys are extensively used as biomedical implant materials because their good mechanical properties are accompanied by an excellent biocompatibility and corrosion resistance. However, the most widely used Ti alloy for medical implants, Ti-6Al-4V, does not satisfy a major requirements about non-toxicity and low elastic modulus clos...

The present work is a study of six as-cast Ti-Co-Cr alloys in the Ti-rich region with the purpose of examining the possibility of obtaining a new β-type Ti-alloys. Two experimental alloys Ti80Co10Cr10 and Ti70Co10Cr20 are nearly single-phases and are identified as bcc β-Ti phase. They also display the lowest hardness values and the best corrosion p...

The present work is a study of six as-cast Ti-Co-Cr alloys in the Ti-rich region with the purpose of examining the possibility of obtaining a new β-type Ti-alloys. Two experimental alloys Ti80Co10Cr10 and Ti70Co10Cr20 are nearly single-phases and are identified as bcc β-Ti phase. They also display the lowest hardness values and the best corrosion p...

The present work is a study of six as-cast Ti-Co-Cr alloys in the Ti-rich region with the purpose of examining the possibility of obtaining a new β-type Ti-alloys. Two experimental alloys Ti80Co10Cr10 and Ti70Co10Cr20 are nearly single-phases and are identified as bcc β-Ti phase. They also display the lowest hardness values and the best corrosion p...

In this paper the effects of cobalt and chromium additions on the microstructure and hardness of as-cast titanium-based alloys was investigated. Ten specimens of Ti-Co-Cr alloys with titanium content ranging from 50 to 80 at. % were prepared by melting the pure elements in a laboratory arc-furnace under argon atmosphere. The microstructure of the a...

In this work 12 dental Co–Cr casting alloys containing titanium in the range of 4–12 wt.% have been studied. Optical and SEM microscopy show that all samples have similar two phases dendritic microstructure. By means of X-ray diffraction two phases of similar compositions were identified as fcc and hcp Co-rich solid solutions. Hardness measurement...

In this paper the effect of thermal treatment on the structure and hardness of dental Co-Cr-Ti alloy was investigated. Among twelve samples of Co-Cr-Ti alloys, wich were prepared by melting the pure elements in an arc-furnace under argon atmosphere Co61Cr35Ti4 alloy was chosen as a representative because of the chemical composition close to the com...

Effect of adding titanium on the microstructure and hardness of as-cast Co-Cr base dental alloys have been investigated with the purpose to determine the region of their optimal characteristics. Twelve samples of Co-Cr-Ti alloys with increasing titanium content (4 to 12 at.%), which were prepared by arc-melting technique in argon atmosphere, reveal...

The properties of Al-Si based foundry alloys are affected by the presence of impurity elements during melting and casting. Iron, as the common impurity element, imparts negative influences on the mechanical properties of these alloys caused by the formation of iron-bearing intermetallic compounds. The influence of iron on the microstructure and har...

Influence of adding titanium on the microstructure and hardness of as-cast cobalt- chromium base alloys have been investigated. Twelve samples of Co-Cr-Ti alloys were prepared by arc-melting technique under argon atmosphere. Using optical metallography and scanning electron microanalyser has been established that all samples have similar two-phases...