Close-coupled atomizers are of great interest and controlling their performance parameters is critical for metal powder producing and spray forming industries. In this study, designed close-coupled nozzle systems were used to investigate the effect of the nozzle types and protrusion length of the melt delivery tube on the pressure formation at the melt delivery tube tip. The observed metal flow rate was not behaving as what was earlier assumed, namely that, deeper aspiration enhanced metal flow rate. Higher aspiration pressure at the tip of the melt delivery tube increases the stability of atomization process.
nanoparticle was synthesized by the flame method, which was controlled by varying the ratio and flow rate of gas mixtures consisting of oxygen (oxidizer), methane (fuel) and nitrogen (carrier gas). The crystalline phases of nanoparticle depended strongly on the temperature distribution in the flame, whereas the morphology was not sensitive. We proved that the anatase phase formed without the phase transformation in the flame and the rutile phase generated through several phase transformations.
A QM-ISP-4 Planetary Mill was employed to activate mechanically the mixtures of anatase and corundum at room temperature for different times. The milled powder mixtures were then sintered at for 1 h. The XRD results showed that the milled powder mixtures were completely transformed into after sintering, except the mixtures milled for 5 and 10 hours. The SEM observations showed the typical morphology of rod-like vary in the range: widths from 0.6 to , and lengths from 3.0 to . The rod-like formation was attributed to the positive effects caused by the mechanical activation.
In the present research work was searched the influence of severe plastic deformation (SPD) realized by ECAP (equalchannel angular pressing) on structural, mechanical and plastic properties of IF (interstitial free) steel. For physical simulation ECAP process with right angle channels was used. The ECAP process was numerical simulated (namely its course of temperature, strain and stress fields and deformation forces) by FormFEM software, too.
In a multi-action tooling system, which is usually used for the powder compaction process to fabricate the complex multilevel parts, crack formation is crucially detrimental and should be avoided. Among various process factors, tool shape is an important factor to prevent the crack formation during powder compaction process. In this work, the effects of different tool shapes were investigated through the experimental oberservation of pore distribution in real products and the finite element analysis of residual stresses. The results were interpreted based on non-uniform powder density in the compacted parts.
Model experiment was introduced to obtain the formation of a core/rim structure by only liquid phase reaction in Ti(C, N)-based cermet alloys. Infiltrated Ti(C, N)-Ni, , and TaC-Ni cermets were bonded to sandwiched specimen by heat treatment for 5hr. With nitrogen addition, both (Ti, Mo) (C, N) and (Ti, Ta) (C, N) rim structure was nucleated around comer of cuboidal Ti(C, N) core. However, equilibrium shapes of(Ti, Mo) (C, N) and (Ti, Ta) (C, N) rim were different possibly due to the effect of interface energy. The core/rim and rim! binder interfaces were parallel to each other with TaC addition, while rotated to each other with addition.
The phylogeneticall y conserved nuclear factor 1 (NFI) gene fami ly encodes s ite-specific tra nscription factors essential for the development of a number of organ syst ems. There are four NFI genes in mamma ls (Nfi a , Nfib, Nfi c, and Nfix) and single NFI genes in Drosophila melanogaster, Caenorhabdi t is elegans, Anopheles spP. ‘ and other simpl e animals. It was reported that Nfia-defici ent mice exhi bit agenesis of the corpus call osum and other forebrain defects , wher eas Nfib-defi cient mice possess unique defects in lung ma turation and fo rebrain defect. Recently, it was also found that Nfic-defi cient mice exhibit agenesis of mo l ar서 roots and severe incisor defects. In the present study, we investigat ed the possible role of NFI-C in odon toblast diffe rent ia tion and root dentin formation using the innovative and invalua ble Nfic knockout mice model Nfi c-defi cient mice showed a berrant odontoblast differentiation and consequentl y abnormal dentin formation, while other t issues/organs in the body including ameloblasts of the enamel organ a ppeared to be unaffec ted and normal One of the most st r iking changes observed in these aberrant odontoblasts was t he absence of in tercellular junctions beLween them, r esulting in di ssociation of the cells and loss of th eir cellular polarity a nd organi zation. Surprisingly, these cells became trapped in dentin-like minerali zed t issue and thus their overa ll morphology r esembled osteoblasts and os t eocyt es. There was also an increased apoptotic activity in Nfic-deficient mice. These findings strongly s uggest ed that NFI -C plays a key role in odon tob last differentiation and survival in a cell type-specific manner.