Ammattikorkeakoulut ja yrityselämä

Yritysten on menestyäkseen ja kilpailussa pärjätäkseen kehityttävä jatkuvasti. Yritykset tarvitsevat kehitystyössään innovaatiovalmiuksia ja sparraavaa tukea. Oulun seudulla on luotu yhteistyöfoorumeita ja kehitetty valmiuksia vastata yritysten tunnistamiin kehittämistarpeisiin. Ammattikorkeakoulujen palvelutarjonta yrityksille on nykyisellään laajaa. Palvelut voivat olla muun muassa koulutus- ja kehittämispalveluja, testaus-, mallinnus- ja tuotekehityspalveluja, yrittäjyyteen liittyviä hautomopalveluja ja tutkimuspalveluja. Ammattikorkeakoulussa eri alojen opiskelijoiden yhteen saattaminen jo opiskeluaikana mahdollistaa innovaatioiden kehittymisen ja laaja-alaisen asioiden tarkastelemisen hallinnolliset raja-aidat ylittäen. Myös kansainvälistymisen lisäämiseen tarvitaan sekä pk- että ammattikorkeakoulusektoreilla lisää innovatiivisia avauksia. Yrityksen voivat myös hyödyntää kansainvälistymisessä ammattikorkeakouluilla jo valmiiksi olevia kansainvälisiä verkostoja. Tuntevatko pk-yritykset riittävästi ammattikorkeakoulujen yrityksille tarjoamia mahdollisuuksia esimerkiksi kehittämistoiminnan kautta? Onko palvelujen käyttämisen kynnys riittävän matala ja ovatko palvelut mahdollisimman helposti saatavilla

Diffusionless isothermal omega transformation in titanium alloys driven by quenched-in compositional fluctuations

In titanium alloys, the ω(hexagonal)-phase transformation has been categorized as either a diffusion-mediated isothermal transformation or an athermal transformation that occurs spontaneously via a diffusionless mechanism. Here we report a diffusionless isothermal ω transformation that can occur even above the ω transformation temperature. In body-centered cubic β-titanium alloyed with β-stabilizing elements, there are locally unstable regions having fewer β-stabilizing elements owing to quenched-in compositional fluctuations that are inevitably present in thermal equilibrium. In these locally unstable regions, diffusionless isothermal ω transformation occurs even when the entire β region is stable on average so that athermal ω transformation cannot occur. This anomalous, localized transformation originates from the fluctuation-driven localized softening of 2/3[111]β longitudinal phonon, which cannot be suppressed by the stabilization of β phase on average. In the diffusionless isothermal and athermal ω transformations, the transformation rate is dominated by two activation processes: a dynamical collapse of {111}β pairs, caused by the phonon softening, and a nucleation process. In the diffusionless isothermal transformation, the ω-phase nucleation, resulting from the localized phonon softening, requires relatively high activation energy owing to the coherent β/ω interface. Thus, the transformation occurs at slower rates than the athermal transformation, which occurs by the widely spread phonon softening. Consequently, the nucleation probability reflecting the β/ω interface energy is the rate-determining process in the diffusionless ω transformations.Tane M., Nishiyama H., Umeda A., et al. Diffusionless isothermal omega transformation in titanium alloys driven by quenched-in compositional fluctuations. Physical Review Materials 3, 043604 (2019); https://doi.org/10.1103/PhysRevMaterials.3.043604

Configurational free energy in order-disorder transitions from Monte Carlo calculations for systems under external fields

A procedure for calculating the configurational free energy with the Monte Carlo simulation is presented, accounting for the case of the application of external fields. First, the free energy for the L10 ordering systems without any external fields has been evaluated for the various values of the second nearest-neighbor effective interaction, and the feature of this method has been discussed from the viewpoint of the pair correlation. Next, this method has been applied to the case of application of external fields, demonstrating the calculation of the free energy under an external stress field for the L10 phase that has a tetragonal distortion dependent on the long-range order parameter

Atomistic study of liquid fragility and spatial heterogeneity of glassy solids in model binary alloys

Abstract Fragility is a fundamental property of glass-forming liquids. Here, we evaluated the liquid fragility and structural and dynamic heterogeneity of glassy solids for four model binary alloys. The most fragile alloy exhibited the maximum dynamic heterogeneity in the mechanical unfreezing process. The local atomic order contributed to structural and dynamic heterogeneities in the glassy solid. We observed that atomic displacement significantly correlated with degrees of clustering of local atomic orders. The clustering produced during the glass-forming quenching process enhanced structural and dynamic heterogeneities, especially in fragile glass alloys. Therefore, this alloy system exhibited correlations among liquid fragility, dynamic heterogeneity in liquid alloys, and dynamic and structural heterogeneities in glassy solids. We discussed the underlying physics of the correlation based on a theoretical model for fragility. These structural and dynamic analyses also provided deeper insights into the features of structural heterogeneity in glassy solids. The alloy with the most fragility exhibited the largest difference in atomic mobility between the densely and loosely packed local atomic orders, implying the greatest heterogeneity in the degree of packing density

Oxidation-State Control of Nanoparticles Synthesized via Chemical Reduction Using Potential Diagrams

A general concept for oxidation-state control of nanoparticles synthesized via chemical reduction has been developed. By comparing kinetically determined mixed potential measured in reaction solution and thermodynamically drawn potential diagrams, e.g., potential–pH diagram, it is possible to know “what chemical species is stable in the reaction solution?.” It is predicted from potential diagrams that nanoparticles in different oxidation states can be selectively synthesized by controlling mixed potential. This concept is verified by selectively synthesizing Cu and Cu2O nanoparticles from CuO aqueous suspension via chemical reduction using the concept as an example. The dependency of mixed potential on pH and temperature is discussed in detail for the selective synthesis of nanoparticles

Correlation of dynamic and quasistatic relaxations: The Cox-Merz rule for metallic glass

The correlation of quasistatic and dynamic relaxations was discussed in a typical strong Zr55Al10Ni5Cu30 metallic glass from room temperature to Tg. The quasistatic relaxation behavior, investigated by high temperature compressive testing at a constant strain rate, was compared with dynamic tensile relaxation behavior. A correlation equation of the dynamic frequency and quasistatic strain rate was successfully deduced, and then its validity was experimentally confirmed in a fragile metallic glass. Using this correlation, the Cox–Merz rule, derived for correlating the steady-state and dynamic viscosities of the polymers, is found to be applicable to metallic glasses