Materials Science Forum
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Paper Title Page
Abstract: The influences of the membership of Finland in the European Union on the structures and
development of the materials research and development, and education are discussed. It will be
shown that during the membership the infrastructure and working culture have changed thoroughly.
1
Abstract: Langmuir-Blodgett films (LB) of hydroxamic amphiphiles were used as coating barriers on metal
surface against corrosion. Two long-chain hydroxamic acids [CH3(CH2)16CONHOH] monolayers in
the presence of some divalent cations (Ca2+, Mg2+, and Cu2+) have been studied at different pH of
the subphase. The monolayer was characterized by surface pressure-area isotherms and visualized
by Brewster angle microscope (BAM).
Compact Langmuir layers were deposited on copper surface, where the modified surfaces were
characterized by contact angle measurement as well as by electrochemical techniques. The
morphology of LB coated copper surface was visualized by atomic force microscopy (AFM). The
coated copper surfaces were tested in corrosive media at acidic and neutral pH. The results show
that the multi-molecular LB films of hydroxamic acid salts form good barriers against copper
corrosion. The comparison of these results with copper coated by LB layers without divalent cations
shows that the presence of divalent cations in the subphase increases the copper corrosion
inhibition. The octadecanoyl hydroxamic acid (C18N) results in better and more stable monolayer
with cations in the subphase.
9
Abstract: The research topic is the analysis of adobe-clay as a structural material. The behaviour of adobe
brick elements of different mixtures were examined. The bricks of various ratios of clay, straw, reed and
sawdust were involved in the experiment, in which the process of drying and shrinkage was investigated.
Even though only a few data have been obtained so far, some important conclusions were drawn. The first
drying period was approximately three weeks long in the laboratory. The tests have shown that organic
components like straw, reed and sawdust slow down the drying process. In case of each mixture, a change
of weight was observed sooner than shrinkage. The aim of the research is to promote the application of
this building material.
17
Abstract: The coated product market is a highly quality exigent market which has been developing
for decades. The technological process of galvanizing starts with a thermal cleaning in a continuous
annealing furnace. Therefore the understanding of the processes which take place before dipping
requires laboratory experiments modelling the oxidation and reduction of the base metal. Some of
the presented experiments are thermogravimetric oxidation and reduction tests, others are laboratory
trials carried out in special experimental furnace.
25
Abstract: The solubility of hydrogen in iron and steels are affected by temperature and crystal
structure. At lower temperatures (below about 400°C), the excess hydrogen, beyond that which is
soluble (and therefore dissolved) interstitially, is retained in the steel in other sites commonly
referred to as ”traps”. At room temperature, the dissolved hydrogen may be only a small fraction
of the total hydrogen content. The movement of hydrogen in steel occurs by the migration of
atoms through the lattice. The hydrogen diffusion takes place with interstitial mechanism.
Trapping enhances the solubility of hydrogen but decreases the diffusivity. In practice hydrogen
transmissibility is characterized by TH value. We have studied the effect of the cold rolling on the
TH value for Al-killed low carbon enamelling-grade steel sheets. The microstructures of the
samples were formed from ferrite, carbides and some non-metallic inclusions. Reducing the
thickness of the steel sheets by cold rolling in carbides appears ruptures, microcavities, and the
dislocation density increases in ferrite grains. Cold work increases the hydrogen permeation time.
The average of TH values after hot rolling was 0.6; after about 72 % thickness reductions by cold
rolling the average TH values was 101.4.
33
Abstract: The wood is one of the most favourable structural material. It appears on all fields of the
ordinary life. It is difficult to say an application where the wood is not used due to its cheap price,
availability and just simply the beauty.
Beside of the wide range of process technologies a new process appeared. This process changes the
properties of the material and brings many new applications to this traditional material. This process
is the compression of the structural wood material.
This publication deals with the effect of the compression on the mechanical properties of two
hardwoods (beech: fagus sylvatica, oak: quercus) by the help of the three-point bending test and the
Charpy impact test.
41
Abstract: The typical tool steels of the wood-cutting industry are the unalloyed and
chromium and nickel containing, low-alloyed eutectoid steels. These materials, in tempered
condition have a very high, 1200-1400 MPa tensile strength. One of the major failure forms
of these tools is the fatigue fracture of the tool. The high pretension and the cyclic load,
caused by the cutting and the bending of the tool, easily can cause high-cycle fatigue fracture,
especially at the welded area and at the heat affected zone. Thus, one of the most critical part
in the manufacturing process of the bandsaw blade is the welding. We have examined the
fatigue properties of three types of joints: conventional and cold wire TIG welding, MIG
welding, and resistance-butt welded joints. The structure at the weld and at the heat affected
zone could highly affect the life-span of the tool. Therefore the welding parameters (preheat,
post welding heat treatment (PWHT), shield gas, backing gas), affecting the microstructure of
the weld, also have serious affects on the fatigue properties. The influence of welding
parameters on the fatigue properties were examined by low-cycle fatigue test.
47
Abstract: Copper alloys have many properties, which make them suitable in wide-ranging
applications in all the engineering industries. For the investigated alloys the most important
properties are hardness, strength and electrical conductivity. Precipitation hardenable alloys were
studied by Jominy end-quench test, in order to examine the change of hardness, electrical
conductivity and microstructure as a length of the test bar (i.e. cooling rate). In the first step samples
were solution treated at different temperatures, then water quenched followed by aging. Cold-work
after quench was applied in some alloys and improve in the properties was clearly seen. The
following Cu-alloys were investigated: Cu-Co-Ni-Be, Cu-2Be-Ni and Cu-2Ni-Be.
55