Automation of machining operations, being result of mass volume production of components, imposes more restrictive requirements

concerning mechanical properties of starting materials, inclusive of machinability mainly. In stage of preparation of material, the

machinability is influenced by such factors as chemical composition, structure, mechanical properties, plastic working and heat treatment,

as well as a factors present during machining operations, as machining type, cutting parameters, material and geometry of cutting tools,

stiffness of the system: workpiece – machine tool – fixture and cutting tool.

In the paper are presented investigations concerning machinability of the EN AC-AlSi9Cu3(Fe) silumin put to refining, modification and

heat treatment. As the parameter to describe starting condition of the alloy was used its tensile strength Rm. Measurement of the machining

properties of the investigated alloy was performed using a reboring method with measurement of cutting force, cutting torque and cutting

power. It has been determined an effect of the starting condition of the alloy on its machining properties in terms of the cutting power,

being indication of machinability of the investigated alloy. The best machining properties (minimal cutting power - Pc=48,3W) were

obtained for the refined alloy, without heat treatment, for which the tensile strength Rm=250 MPa. The worst machinability (maximal

cutting power Pc=89,0W) was obtained for the alloy after refining, solutioning at temperature 510 o

C for 1,5 hour and aged for 5 hours at

temperature 175 o

C. A further investigations should be connected with selection of optimal parameters of solutioning and ageing

treatments, and with their effect on the starting condition of the alloy in terms of improvement of both mechanical properties of the alloy

and its machining properties, taking into consideration obtained surface roughness.

The paper is a presentation of a study on issues concerning degradation of protective paint coat having an adverse impact on aesthetic

qualities of thin-walled cast-iron castings fabricated in furan resin sand. Microscopic examination and microanalyses of chemistry

indicated that under the coat of paint covering the surface of a thin-walled casting, layers of oxides could be found presence of which can

be most probably attributed to careless cleaning of the casting surface before the paint application process, as well as corrosion pits

evidencing existence of damp residues under the paint layers contributing to creation of corrosion micro-cells

The suspension of the copper droplets in the post-processing slag taken directly from the KGHM-Polska Miedź S.A. Factory (from the

direct-to-blister technology as performed in the flash furnace) was subjected to the special treatment with the use of the one of the typical

industrial reagent and with the complex reagent newly patented by the authors. This treatment was performed in the BOLMET S.A.

Company in the semi-industrial conditions. The result of the CaCO3, and Na2CO3 chemicals influence on the coagulation and subsequent

sedimentation of copper droplets on the crucible bottom were subjected to comparison with the sedimentation forced by the mentioned

complex reagent. The industrial chemicals promoted the agglomeration of copper droplets but the coagulation was arrested / blocked by

the formation of the lead envelope. Therefore, buoyancy force forced the motion of the partially coagulated copper droplets towards the

liquid slag surface rather than sedimentation on the crucible bottom. On the other hand, the complex reagent was able to influence the

mechanical equilibrium between copper droplets and some particles of the liquid slag as well as improve the slag viscosity. Finally, the

copper droplets coagulated successfully and generally, were subjected to a settlement on the crucible bottom as desired / requested.

The main bulk density representation in the molding material is opening material, refractory granular material with a particle size of 0.02

mm. It forms a shell molds and cores, and therefore in addition to activating the surface of the grain is one of the most important features

angularity and particle size of grains. These last two features specify the porosity and therefore the permeability of the mixture, and

thermal dilatation of tension from braking dilation, the thermal conductivity of the mixture and even largely affect the strength of molds

and cores, and thus the surface quality of castings. [1]

Today foundries, which use the cast iron for produce of casts, are struggling with surface defects on the casts. One of these defects are

veining. They can be eliminated in several ways. Veining are foundry defects, which arise as a result of tensions generated at the interface

of the mold and metal. This tension also arises due to abrupt thermal expansion of silica sand and is therefore in the development of

veining on the surface of casts deal primarily influences and characteristics of the filler material – opening material in the production of

iron castings.

A356 is one of the widely used aluminium casting alloy that has been used in both sand and die casting processes. Large amounts of scrap

metal can be generated from the runner systems and feeders. In addition, chips are generated in the machined parts. The surface area with

regard to weight of chips is so high that it makes these scraps difficult to melt. Although there are several techniques evolved to remedy

this problem, yet the problem lies in the quality of the recycled raw material. Since recycling of these scrap is quite important due to the

advantages like energy saving and cost reduction in the final product, in this work, the recycling efficiency and casting quality were

investigated. Three types of charges were prepared for casting: %100 primary ingot, %100 scrap aluminium and fifty-fifty scrap

aluminium and primary ingot mixture were used. Melt quality was determined by calculating bifilm index by using reduced pressure test.

Tensile test samples were produced by casting both from sand and die moulds. Relationship between bifilm index and tensile strength were

determined as an indication of correlation of melt quality. It was found that untreated chips decrease the casting quality significantly.

Therefore, prior to charging the chips into the furnace for melting, a series of cleaning processes has to be used in order to achieve good

quality products.

To improve mechanical properties and increasing useful life of metal pieces, different methods of welding are used for repairing surface

crack of metal pieces. In this research, performance of flame welding method by spraying pure iron powder evaluated for repairing surface

grooves of structural steel. First, four specimens including one control specimen and other three specimens grooved specimens in depth of

1mm and in length of 12.5mm and groove width in the sizes of 0.5, 0.75 and 1mm.were prepared then, powder melted using oxyacetylene

reducing flame and spraying iron powder in the flame path and attached to the inner surface of the groove and finally, the specimen

repaired. Results showed that after repairing surface groove, tensile strength of the repaired specimens were reached to the tensile strength

of control specimen with the margin of 2.5%.

The paper presents an original method of measuring the actual chromite content in the circulating moulding sand of foundry. This type of

material is applied for production of moulds. This is the case of foundry which most frequently perform heavy casting in which for the

construction of chemical hardening mould is used, both the quartz sand and chromite sand. After the dry reclamation of used moulding

sand, both types of sands are mixed in various ratios resulting that in reclaimed sand silos, the layers of varying content of chromite in

mixture are observed. For chromite recuperation from the circulating moulding sand there are applied the appropriate installations

equipped with separate elements generating locally strong magnetic field. The knowledge of the current ratio of chromite and quartz sand

allows to optimize the settings of installation and control of the separation efficiency. The arduous and time-consuming method of

determining the content of chromite using bromoform liquid requires operational powers and precautions during using this toxic liquid.

It was developed and tested the new, uncomplicated gravimetric laboratory method using powerful permanent magnets (neodymium).

The method is used in the production conditions of casting for current inspection of chromite quantity in used sand in reclamation plant.

In the paper, a relationship between chemical composition of Ni-Mn-Cu cast iron and its structure, hardness and corrosion resistance is

determined. The examinations showed a decrease of thermodynamic stability of austenite together with decreasing nickel equivalent value,

in cast iron solidifying according to both the stable and the metastable systems. As a result of increasing degree of austenite

transformation, the created martensite caused a significant hardness increase, accompanied by small decline of corrosion resistance. It was

found at the same time that solidification way of the alloy and its matrix structure affect corrosion resista

The paper presents a practical example of improvement of foundry production systems in terms of post-finishing of nodular iron castings

produced in the conditions of bulk production for automotive industry. The attention was paid to high labour-intensive efforts, which

are difficult to be subjected to mechanization and automation. The times of actions related to grinding processing of castings in three

grinding positions connected with a belt conveyor were estimated with the use of a time study method. A bottleneck as well as limiting

factors were specified in a system. A number of improvements were proposed, aimed at improving work organization on the castings postfinishing

line. An analysis of work ergonomics at the workplace was made in order to eliminate unnecessary and onerous for the employee

actions. A model of production system using the Arena software, on which a simulation experiment was conducted, was drawn up in order

to visualize the analysed phenomena. The effects of the project were shown on graphs comparing times, costs, work ergonomics and

overall efficiency of production equipment indicator.

In the paper the reasons for steam pipeline’s elbow material rupture, made of steel 13CrMo4-5 (15HM) that is being used in the energetics.

Based on the mechanical properties in the ambient temperature (Rm, Rp0,2 and elongation A5) and in the increased temperature (Rp0,2t

) it

was found, that the pipeline elbow’s material sampled from the ruptured area has lower Rp0,2 i Rp0,2t by around 2% than it is a requirement

for 13CrMo4-5 steel in it’s base state. The damage appeared as a result of complex stress state, that substantially exceeded the admissible

tensions, what was the consequence of considerable structure degradation level. As a result of the microstructure tests on HITACHI S4200

microscope, the considerable development of the creeping process associates were found. Also the advances progress of the microstructure

degradation was observed, which is substantial decomposition of bainite and multiple, with varied secretion size, and in most cases

forming the micro cracks chains. With the use of lateral micro sections the creeping voids were observed, that creates at some places the

shrinkage porosities clusters and micro pores.

Within the presented work, the effect of austenite transformation on abrasive wear as well as on rate and nature of corrosive destruction

of spheroidal Ni-Mn-Cu cast iron was determined. Cast iron contained: 3.1÷3.4 %C, 2.1÷2.3 %Si, 2.3÷3.3 %Mn, 2.3÷2.5 %Cu and

4.8÷9.3 %Ni. At a higher degree of austenite transformation in the alloys with nickel equivalent below 16.0%, abrasive wear resistance

was significantly higher. Examinations of the corrosion resistance were carried out with the use of gravimetric and potentiodynamic

method. It was shown that higher degree of austenite transformation results in significantly higher abrasive wear resistance and slightly

higher corrosion rate, as determined by the gravimetric method. However, results of potentiodynamic examinations showed creation

of a smaller number of deep pinholes, which is a favourable phenomenon from the viewpoint of corrosion resistance.

The welding technologies are widely used for design of protection layer against wear and corrosion. Hardfacing, which is destined for

obtaining coatings with high hardness, takes special place in these technologies. One of the most effective way of hardfacing is using self

shielded flux cored arc welding (FCAW-S). Chemical composition obtained in flux cored wire is much more rich in comparison to this

obtained in solid wire. The filling in flux cored wires can be enriched for example with the mixture of hard particles or phases with

specified ratio, which is not possible for solid wires. This is the reason why flux cored wires give various possibilities of application of this

kind of filler material for improving surface in mining industry, processing of minerals, energetic etc. In the present paper the high

chromium and niobium flux cored wire was used for hardfacing process with similar heat input. The work presents studies of

microstructures of obtained coatings and hardness and geometric properties of them. The structural studies were made with using optical

microscopy and X- ray diffraction that allowed for identification of carbides and other phases obtained in the structures of deposited

materials. Investigated samples exhibit differences in coating structures made with the same heat input 4,08 kJ/mm. There are differences

in size, shape and distribution of primary and eutectic carbides in structure. These differences cause significant changes in hardness of

investigated coatings.

The present research was conducted on thin-walled castings with 5 mm wall thicknesses. This study addresses the effect of the influence of

different master alloys, namely: (1) Al-5%Ti-1%B, (2) Al-5%Ti and (3) Al-3%B, respectively on the structure and the degree of

undercooling (ΔTα = Tα-Tmin, where Tα - the equilibrium solidification temperature, Tmin - the minimum temperature at the beginning of

α(Al) solidification) of an Al-Cu alloy. The process of fading has been investigated at different times spent on the refinement treatment ie.

from 3, 20, 45 and 90 minutes respectively, from the dissolution of master alloys. A thermal analysis was performed (using a type-S

thermocouple) to determine cooling curves. The degree of undercooling and recalescence were determined from cooling and solidification

curves, whereas macrostructure characteristics were conducted based on a metallographic examination. The fading effect of the refinement

of the primary structure is accompanied by a significant change in the number (dimension) of primary grains, which is strongly correlated

to solidification parameters, determined by thermal analysis. In addition to that, the analysis of grain refinement stability has been shown

with relation to different grain refinements and initial titanium concentration in Al-Cu base alloy. Finally, it has been shown that the

refinement process of the primary structure is unstable and requires strict metallurgical control.

Ensuring the required quality of castings is an important part of the production process. The quality control should be carried out in a fast

and accurate way. These requirements can be met by the use of an optical measuring system installed on the arm of an industrial robot. In

the article a methodology for assessing the quality of robotic measurement system to control certain feature of the casting, based on the

analysis of repeatability and reproducibility is presented. It was shown that industrial robots equipped with optical measuring systems have

the accuracy allowing their use in the process of dimensional control of castings manufactured by lost-wax process, permanent-mould

casting, and pressure die-casting.

The paper presents the microstructure and selected properties of ausferritic nodular cast iron annealed at the temperature 520 and 550°C.

This choice was dictated by the temperatures used in the practice of nitriding. Nodular graphite in cast iron was obtained with use of

Inmold process. Cast iron containing molybdenum and copper ensuring obtaining an ausferrite in the cast iron matrix without the use of

heat treatment of castings was tested. The effect of annealing temperature on the microstructure and the kind of fracture of the ausferritic

nodular cast iron was presented. The effect of an annealing temperature on hardness, impact strength and the microhardness of ausferritic

nodular cast iron matrix was shown too. The lamellar structure of phases in the cast iron matrix after annealing has been ascertained. There

has been an increase in hardness of an annealed cast iron and microhardness of its matrix. The reduction in the impact strength of the cast

iron annealed at 520 and 550°C was approximately 10-30%. Both an increase in the hardness of cast iron as well as an decrease in its

impact strength is probably due to the separation of secondary carbides during the heat treatment.

The paper presents the use of rapid prototyping technology of three dimensional printing (3DP) to make a prototype shell casting mold. In

the first step, for identification purposes, a mold was prepared to enable different alloys to be cast. All molds being cast were designed in a

universal CAD environment and printed with the zp151 composite material (Calcium sulfate hemihydrate) with a zb63 binder (2-

pyrrolidone). It is designated to be used to prepare colourful models presenting prototypes or casting models and molds. The usefulness of

3DP technology for use with copper alloys, aluminum and zinc was analyzed. The strength of the mold during casting was assumed as a

characteristic comparative feature in the material resistance to high temperature, the quality of the resulting casting and its surface

roughness. Casting tests were carried out in vacuum – pressure casting. The casting programs applied, significantly increased the quality of

castings and enabled precise mold submergence. Significant improvement was noted in the quality compared to the same castings obtained

by gravity casting.

The paper presents tribological properties of A390.0 (AlSi17Cu5Mg) alloy coupled in abrasive action with EN-GJL-350 grey cast-iron.

The silumin was prepared with the use of two different technologies which differed in terms of cooling speed. In the first case the alloy

was modified with foundry alloy CuP10 and cast to a standard tester ATD and in case of second option the modified alloy was cast into

steel casting die. Due to different speed of heat removal the silumins varied in structure, particularly with size of primary crystals of silicon

and their distribution in matrix which had a significant influence of friction coefficient in conditions of dry friction.

This article presents the results of studies in the hypoeutectic silumin destined for pressure die casting with the simultaneous addition of

chromium and tungsten. The study involved the derivative and thermal analysis of the crystallization process, metallographic analysis and

mechanical properties testing. Silumin 226 grade was destined for studies. It is a typical silumin to pressure die casting. AlCr15 and AlW8

preliminary alloys were added to silumin. Its quantity allowed to obtain 0.1, 0.2, 0.3 and 0.4% of Cr and W in the tested alloy. Studies of

the crystallization process as well as the microstructure of the silumin poured into DTA sampler allowed to state the presence of additional

phase containing 0.2% or more Cr and W. It has not occurred in silumin without the addition of above mentioned elements. It is probably

the intermetallic phase containing Cr and W. DTA studies have shown this phase crystallizes at a higher temperature range than α (Al)

solid solution. In the microstructure of each pressure die casting containing Cr and W the new phases formed. Mechanical properties tests

have shown Cr and W additives in silumin in an appropriate amount may increase its tensile strength Rm (about 11%), the yield strength

Rp0.2 (about 21%) and to a small extent elongation A.

In the paper, presented is a research on effectiveness of absorbing electromagnetic waves at frequency 2.45 GHz by unhardened moulding

sands prepared of three kinds of high-silica base and a selected grade of sodium silicate. Measurements of power loss of microwave

radiation (Pin) expressed by a total of absorbed power (Pabs), output power (Pout) and reflected power (Pref) were carried-out on a stand of

semiautomatic microwave slot line. Values of microwave power loss in the rectangular waveguide filled with unhardened moulding sands

served for determining effectiveness of microwave heating. Balance of microwave power loss is of technological and economical

importance for manufacture of high-quality casting moulds and cores of various shapes and sizes. It was found that relative density

influences parameters of power output and power reflected from samples of moulding sand placed in a waveguide. Absorption expressed

by the parameter Pabs is not related to granularity of high-silica base: fine, medium and coarse. It was found that the semiautomatic

microwave slot line supports evaluation of effectiveness of microwave absorption on the grounds of power loss measurements and enables

statistic description of influence of relative density of the sandmix on penetration of electromagnetic waves in unhardened moulding sands.

Refinement is one of the most energy consuming technological process, aimed at obtaining mineral raw materials of the proper grain size.

Cast structural elements such as jaws or hammers in crushing machines operate under conditions of an intensive wear. The data indicate

that 80 % of failures of machines and devices is caused by wearing of rubbing surfaces. This problem became the subject of several

scientific and industrial investigations carried out in the whole world in order to produce materials ultra- wear resistant. Methods allowing

to obtain wear resistant composite castings are discussed in the hereby paper. Within the performed research microstructures of the

produced composite zones were presented and the comparative analysis with regard to mechanical and functional properties of local

composite reinforcements in relation to the commercial alloys of increased wear resistance was performed. The results show almost twenty

five times increase in wear resistance compared to manganese cast steel containing 18 % Mn.

Moulding properties of Isasa River Sand bonded with Ipetumodu clay (Ife-North Local Government Area, Osun State, Nigeria) were

investigated. American Foundry men Society (AFS) standard cylindrical specimens 50mm diameter and 50mm in height were prepared

from various sand and clay ratios (between 18% and 32%) with 15% water content. The stress-strain curves were generated from a

universal strength testing machine. A flow factor was calculated from the inclination of the falling slope beyond the maximum

compressive strength. The result shows that the flowability of the samples increases from 18% to 26% clay content, its maximum value

was attained at 26% and then it decreases from 30% to 32% clay content. The green compressive strength, dry compressive strength and

air permeability values obtained from the mould samples were in accordance with standard values used in foundry practice. The x-ray

diffraction test shows that the sand contains silicon oxide (SiO2), Aluminium oxide (Al2O3), and Aluminium silicate (Al6Si2O13). The

mould samples were heated to a temperature of 1200 o

C to determine the sintering temperature; fussion did not take place at this

temperature. The results showed that the sand and clay mixture can be used to cast ferrous and non-ferrous alloys.

Heat treatment of a casting elements poured from silumins belongs to technological processes aimed mainly at change of their mechanical

properties in solid state, inducing predetermined structural changes, which are based on precipitation processes (structural strengthening of

the material), being a derivative of temperature and duration of solutioning and ageing operations. The subject-matter of this paper is the

issue concerning implementation of a heat treatment process, basing on selection of dispersion hardening parameters to assure

improvement of technological quality in terms of mechanical properties of a clamping element of energy network suspension, poured from

hypoeutectic silumin of the LM25 brand; performed on the basis of experimental research program with use of the ATD method, serving

to determination of temperature range of solutioning and ageing treatments. The heat treatment performed in laboratory conditions on a

component of energy network suspension has enabled increase of the tensile strength Rm and the hardness HB with about 60-70%

comparing to the casting without the heat treatment, when the casting was solutioned at temperature 520 o

C for 1 hour and aged at

temperature 165 o

C during 3 hours.

The influence of the refractory coating which is a mixture of silica flour and kaolin on the surface roughness of the plate castings produced

using evaporative patterns had been considered in this work. The kaolin was used as a binder and ratio method was employed to form basis

for the factorial design of experiment which led to nine runs of experiments. Methyl alcohol at 99% concentration was used as the carrier

for the transfer of the coating to the surface of the patterns. Pouring temperature was observed as a process parameter alongside the mix

ratios of the coating. Attempts were made to characterize the refractory coating by using two methods; differential thermal analysis (DTA)

and X-ray diffraction. Attempt was also made to characterize the casting material. Gating system design was done for the plate casting to

determine the correct proportions of the gating parameters in order to construct the gating system properly to avoid turbulence during

pouring of liquid metal. A digital profilometer was used to take the measurements of the surface roughness. It was observed that the mix

ratio 90% silica flour-10% kaolin produced the lowest value of the surface roughness of the plate castings and had the lowest material loss

in the DTA test. The pouring temperature of 650o

C produced best casting.

Trial series of cast alloy MO59 obtained from qualified scrap was investigated. SEM and TEM of resulting precipitates were conducted.

The SEM analysis demonstrated the dependence of silicon, phosphorus, iron, chromium and nickel in the composition of the so-called

hard precipitates. TEM analysis showed the formation of phase AlFeSi and AlCr. Made studies have shown the important role of the

composition of the batch melts brass CuZn39Pb2 type. The analysis of SEM and TEM resulting precipitates pointed to the formation of

various forms of divisions, only one of which was described in the literature character of the so-called hard inclusions. The SEM studies

demonstrated the dependence of the occurrence of inclusions rich in silicon, phosphorus, iron, chromium and nickel. In contrast, additional

TEM analysis indicated the formation of AlFeSi phase type and AlCr. The results of the analyses referred to the structure of the batch. Due

to the difficulty of obtaining recycled materials that do not contain these elements necessary to carry out further analyzes in the direction

of defining the role of phosphorus in the formation of the so-called hard inclusions.