Growing emission requirements are forcing the foundry industry to seek new, more environmentally friendly solutions. One of the

solutions may be the technologies of preparing moulding and core sands using organic biodegradable materials

as binders. However, not only environmental requirements grow but also those related to the technological properties

of moulding sand. Advancing automation and mechanization of the foundry industry brings new challenges related to the moulding sands.

Low elasticity may cause defects during assembly of cores or moulds by the manipulators.

The paper presents the study of flexibility in the room temperature according to new method and resistance to thermal deformation of selfhardening

moulding sands with furfuryl resin, containing biodegradable material PCL. The task of the new additive is to reduce the

moulding sands harmfulness to the environment and increase its flexibility in the room temperature. The impact of the additive and the

effect of the amount of binder on the properties of mentioned moulding sands were analysed. Studies have shown that the use of 5% of

PCL does not change the nature of the thermal deformation curve, improves the bending strength of tested moulding mixtures and

increases their flexibility at room temperature.

The article shows the influence of environment requirements on changes in different foundry moulding sands technologies such as cold

box, self-hardening moulding sands and green sands. The aim of the article is to show the possibility of using the biodegradable materials

as binders (or parts of binders’ compositions) for foundry moulding and core sands. The authors concentrated on the possibility of

preparing new binders consisting of typical synthetic resins - commonly used in foundry practice - and biodegradable materials. According

to own research it is presumed that using biodegradable materials as a part of new binders’ compositions may cause not only lower toxicity

and better ability to reclaim, but may also accelerate the biodegradation rate of used binders. What’s more, using some kinds of

biodegradable materials may improve flexibility of moulding sands with polymeric binder. The conducted research was introductory and

took into account bending strength and thermal properties of furan moulding sands with biodegradable material (PCL). The research

proved that new biodegradable additive did not decrease the tested properties.

This paper focuses on mechanical properties of self hardening moulding sands with furfuryl and alkyd binders. Elasticity as a new

parameter of moulding sands is investigated. With the use of presented testing equipment, it is possible to determine force kinetics and

deformation of moulding sand in real time. The need for this kind of study comes from the modern casting industry. New foundries can be

characterized with high intensity of production which is correlated with high level of mechanization and automatization of foundry

processes. The increasingly common use of manipulators in production of moulds and cores can lead to generation of new types of flaws,

caused by breakage in moulds and cores which could occur during mould assembly. Hence it is required that moulds and cores have high

resistance to those kinds of factors, attributing it with the phenomenon of elasticity. The article describes the theoretical basis of this

property, presents methods of measuring and continues earlier research.

Recently, some major changes have occurred in the structure of the European foundry industry, such as a rapid development in the production of castings from compacted graphite iron and light alloys at the expense of limiting the production of steel castings. This created a significant gap in the production of heavy steel castings (exceeding the weight of 30 Mg) for the metallurgical, cement and energy industries. The problem is proper moulding technology for such heavy castings, whose solidification and cooling time may take even several days, exposing the moulding material to a long-term thermal and mechanical load. Owing to their technological properties, sands with organic binders (synthetic resins) are the compositions used most often in industrial practice. Their main advantages include high strength, good collapsibility and knocking out properties, as well as easy mechanical reclamation. The main disadvantage of these sands is their harmful effect on the environment, manifesting itself at various stages of the casting process, especially during mould pouring. This is why new solutions are sought for sands based on organic binders to ensure their high technological properties but at the same time less harmfulness for the environment. This paper discusses the possibility of reducing the harmful effect of sands with furfuryl binders owing to the use of resins with reduced content of free furfuryl alcohol and hardeners with reduced sulphur content. The use of alkyd binder as an alternative to furfuryl binder has also been proposed and possible application of phenol-formaldehyde resins was considered.

The constantly developing and the broadly understood automation of production processes in foundry industry, creates both new working conditions - better working standards, faster and more accurate production - and new demands for previously used materials as well as opportunities to generate new foundry defects. Those high requirements create the need to develop further the existing elements of the casting production process. This work focuses on mechanical and thermal deformation of moulding sands prepared in hot-box technology. Moulding sands hardened in different time periods were tested immediately after hardening and after cooling. The obtained results showed that hardening time period in the range 30-120 sec does not influence the mechanical deformation of tested moulding sands significantly. Hot distortion tests proved that moulding sands prepared in hot-box technology can be characterized with stable thermal deformation up to the temperature of circa 320oC.

Modern techniques of castings production, including moulding sands production, require a strict technological regime and high quality

materials. In the case of self-hardening moulding sands with synthetic binders those requirements apply mainly to sand, which adds to

more than 98% of the whole moulding sand mixture. The factors that affect the quality of the moulding sands are both chemical (SiO2

,

Fe2O3 and carbonates content) and physical. Among these factors somewhat less attention is paid to the granulometric composition of the

sands. As a part of this study, the effect of sand quality on bending strength Rgu

and thermal deformation of self-hardening moulding sands

with furfural and alkyd resin was assessed. Moulding sands with furfural resin are known [1] to be the most susceptible to the sand quality.

A negative effect on its properties has, among others, high content of clay binder and so-called subgrains (fraction smaller than 0,1mm),

which can lead to neutralization of acidic hardeners (in the case of moulding sands with furfuryl resin) and also increase the specific

surface, what forces greater amount of binding agents. The research used 5 different quartz sands originating from different sources and

characterized with different grain composition and different clay binder content.

The paper presents possibility of using biodegradable materials as parts of moulding sands’ binders based on commonly used in foundry

practice resins. The authors focus on thermal destruction of binding materials and thermal deformation of moulding sands with tested

materials. All the research is conducted for the biodegradable material and two typical resins separately. The point of the article is to show

if tested materials are compatible from thermal destruction and thermal deformation points of view. It was proved that tested materials

characterized with similar thermal destruction but thermal deformation of moulding sands with those binders was different.

This paper presents a new perspective on the issue of reclamation of moulding and core sands. Taking as a premise that the reclamation process must remain on the surface of grains some not separated binding materials rests, it should be chosen the proper moulding sand’s composition that will be least harmful for the reclaim quality. There are two different moulding and core sands taken into examinations. The researches prove that a small correction of their compositions (hardener type) improves the quality of the received reclaims. Carried out in this article studies have shown that such an approach to the problem of reclamation of the moulding and core sands is needed and reasonable.

The constant growth of foundry modernization, mechanization and automation is followed with growing requirements for the quality and parameters of both moulding and core sands. Due to this changes it is necessary to widen the requirements for the parameters used for their quality evaluation by widening the testing of the moulding and core sands with the measurement of their resistance to mechanical deformation (further called elasticity). Following article covers measurements of this parameter in chosen moulding and core sands with different types of binders. It focuses on the differences in elasticity, bending strength and type of bond destruction (adhesive/cohesive) between different mixtures, and its connection to the applied bonding agent. Moulding and cores sands on which the most focus is placed on are primarily the self-hardening moulding sands with organic and inorganic binders, belonging to the group of universal applications (used as both moulding and core sands) and mixtures used in cold-box technology.

The ablation casting technology consists in pouring castings in single-use moulds made from the mixture of sand and watersoluble binder. After pouring the mould with liquid metal, while the casting is still solidifying, the mould destruction (washing out, erosion) takes place using a stream of cooling medium, which in this case is water. The following paper focuses on the selection of moulding sands with hydrated sodium silicate technologies for moulds devoted to the ablation casting of aluminum alloys. It has been proposed to use different types of moulding sands with a water-soluble binder, which is hydrated sodium silicate. The authors showed that the best kind of moulding sands for moulds for Al alloy casting will be moulding sands hardened with physical factors – through dehydration. The use of microwave hardened moulding sands and moulding sands made in hot-box technology has been proposed. The tests were carried out on moulding sands with different types of modified binder and various inorganic additives. The paper compares viscosity of different binders used in the research and thermal degradation of moulding sands with tested binders. The paper analyzes the influence of hardening time periods on bending strength of moulding sands with hydrated sodium silicate prepared in hot-box technology. The analysis of literature data and own research have shown that molding sand with hydrated sodium silicate hardened by dehydration is characterized by sufficient strength properties for the ablation foundry of Al alloys.

The paper deals with the influence of manganese in AlSi7Mg0.3 alloy with higher iron content. Main aim is to eliminate harmful effect of intermetallic – iron based phases. Manganese in an alloy having an iron content of about 0.7 wt. % was graded at levels from 0.3 to 1.4 wt. %. In the paper, the effect of manganese is evaluated with respect to the resulting mechanical properties, also after the heat treatment (T6). Morphology of the excluded intermetallic phases and the character of the crystallisation of the alloy was also evaluated. From the obtained results it can be concluded that the increasing level of manganese in the alloy leads to an increase in the temperature of the β-Al5FeSi phase formation and therefore its elimination. Reducing the amount of β-Al5FeSi phase in the structure results in an improvement of the mechanical properties (observed at levels of 0.3 to 0.8 wt. % Mn). The highest addition of Mn (1.4 wt.%) leads to a decrease in the temperature corresponding to the formation of eutectic silicon, which has a positive influence on the structure, but at the same time the negative sludge particles were also present

Main aim of submitted work is evaluation and experimental verification of inoculation effect on Al alloys hot-tear sensitivity. Submitted work consists of two parts. The first part introduces the reader to the hot tearing in general and provides theoretical analysis of hot tearing phenomenon. The second part describes strontium effect on hot tearing susceptibility, and gives the results on hot tearing for various aluminium alloys. During the test, the effect of alloy chemical composition on hot tearing susceptibility was also analyzed. Two different Al-based alloys were examined. Conclusions deals with effect of strontium on hot tearing susceptibility and confirms that main objective was achieved.

Casting industry has been enriched with the processes of mechanization and automation in production. They offer both better working standards, faster and more accurate production, but also have begun to generate new opportunities for new foundry defects. This work discusses the disadvantages of processes that can occur, to a limited extend, in the technologies associated with mould assembly and during the initial stages of pouring. These defects will be described in detail in the further part of the paper and are mainly related to the quality of foundry cores, therefore the discussion of these issues will mainly concern core moulding sands. Four different types of moulding mixtures were used in the research, representing the most popular chemically bonded moulding sands used in foundry practise. The main focus of this article is the analysis of the influence of the binder type on mechanical and thermal deformation in moulding sands.

The essence of ablation casting technology consists in pouring castings in single-use moulds made from the mixture of sand and a watersoluble binder. After pouring the mould with liquid metal, while the casting is still solidifying, the mould destruction (washing out, erosion) takes place using a stream of cooling medium, which in this case is water. This paper focuses on the selection of moulding sands with hydrated sodium silicate for moulds used in the ablation casting. The research is based on the use of Cordis binder produced by the Hüttenes-Albertus Company. It is a new-generation inorganic binder based on hydrated sodium silicate. Its hardening takes place under the effect of high temperature. As part of the research, loose moulding mixtures based on the silica sand with different content of Cordis binder and special Anorgit additive were prepared. The reference material was sand mixture without the additive. The review of literature data and the results of own studies have shown that moulding sand with hydrated sodium silicate hardened by dehydration is characterized by sufficient strength properties to be used in the ablation casting process. Additionally, at the Foundry Research Institute in Krakow, preliminary semi-industrial tests were carried out on the use of Cordis sand technology in the manufacture of moulds for ablation casting. The possibility to use these sand mixtures has been confirmed in terms of both casting surface quality and sand reclamation.