559 research outputs found
Search for quantum criticality in a ferromagnetic system UNi1-xCoxSi2
Polycrystalline samples of the isostructural alloys UNi1-xCoxSi2 (0 <= x <=
1) were studied by means of x-ray powder diffraction, magnetization, electrical
resistivity and specific heat measurements, at temperatures down to 2 K and in
magnetic fields up to 5 T. The experimental data revealed an evolution from
strongly anisotropic ferromagnetism with pronounced Kondo effect, observed for
the alloys with x < 0.98 and being gradually suppressed with rising Co-content,
to spin-glass-like states with dominant spin fluctuations, seen for the sample
with x = 0.98. Extrapolation of the value of TC(x) yields a critical
concentration xc = 1, at which the magnetic ordering entirely disappears. This
finding is in line with preliminary data collected for stoichiometric UCoSi2.Comment: to appear in Phys. Rev.
The Influence of Ingate Size on the Lost Foam Casting Process
The article presents analysis of the influence of ingate size on the Lost Foam casting process. In particular, analysis of simulation tests has been carried out to determine the ingate size influence on the rate of filling of the mould cavity, pressure in the gas gap and size of the gas gap. A specially prepared mathematical model of the process and an original calculation algorithm were used in simulation tests of full-mould casting. The tests have indicated that the increase of the ingate size results in the increase of filling rate and increase of pressure of gases in the gas gap. However, significant influence on mould cavity filling occurs only when the ingate size is less than ~1 cm2
Optimization of Master Alloy Amount and Gating System Design for Ductile Cast Iron Obtain in Lost Foam Process
The paper presents the optimization of master alloy amount for the high nodular graphite yield (80-90%) in cast iron obtain in lost foam process. The influence of the gating system configuration and the shape of the reaction chamber, the degree of spheroidisation cast iron was examined. Research has shown that the, optimal of master alloy amount of 1.5% by mass on casting iron. The degree of spheroidisation is also influenced by the gating system configuration. The best spheroidisation effect was obtained for liquid cast iron was fed into the reaction chamber from the bottom and discharged from the top
Influence of time and pressure of forming a pattern on mechanical properties
In this paper, the technology of forming patterns on a research station equipped with an autoclave A-600 of Polish company GROM is presented. This study was conducted to determine the influence of pressure and time of forming a pattern on the bending strength. Analysis of the results confirmed that bending strength increases with increasing the pressure. The time of forming a pattern has a similar effect
- …