Enhancing oxidation resistance of Cu during repeated melting by the in-situ formation of protective oxide films

2021 ◽  
Vol 286 ◽  
pp. 129234
Author(s):  
Yongli Guo ◽  
Hui Cai ◽  
Zhe Wang ◽  
Xin Wang ◽  
Peng Cao ◽  
...  
Keyword(s):  
Oxidation Resistance ◽  
Oxide Films ◽  
Protective Oxide ◽  
In Situ Formation

High Temperature Oxidation Behavior of Al Added Mo / Mo5SiB2in-situ Composites

2004 ◽  
Vol 842 ◽  
Author(s):  
Akira Yamauchi ◽  
Kyousuke Yoshimi ◽  
Shuji Hanada
Keyword(s):  
Oxidation Resistance ◽  
Oxidation Behavior ◽  
Mass Gain ◽  
Protective Oxide ◽  
Initial Oxidation ◽  
Temperature Oxidation ◽  
Temperature Range ◽  
Crystalline Oxides ◽  
Rapid Mass

ABSTRACTIsothermal oxidation behavior of Mo/Mo5SiB2in-situ composites containing small amounts of Al was investigated under an Ar-20%O2 atmosphere in the temperature range of 1073–1673 K. The Mo/Mo5SiB2in-situ composites, (Mo-8.7mol%Si-17.4mol%B)100-xAlx (x=0, 1, 3, and 5mol%), were prepared by Ar arc-melting, and then homogenized at 2073 K for 24 h in an Ar-flow atmosphere. Without addition of Al, Mo/Mo5SiB2in-situ composite exhibits a rapid mass loss at the initial oxidation stage, followed by passive oxidation after the substrate is sealed with borosilicate glass in the temperature range of 1173–1473 K, whereas it exhibits a rapid mass gain around 1073 K. On the other hand, small Al additions, especially of 1 mol%, significantly improve the oxidation resistance of Mo/Mo5SiB2in-situ composites at temperatures from 1073–1573 K. The excellent oxidation resistance is considered to be due to the rapid formation of a continuous, dense scale of Al-Si-O complex oxides. The protective oxide scales contain crystalline oxides, and the amounts of the crystalline oxides obviously increase with Al concentration.

scholarly journals Formation of compact systems of super-Earths via dynamical instabilities and giant impacts

2019 ◽  
Vol 491 (4) ◽  
pp. 5595-5620 ◽  
Author(s):  
Sanson T S Poon ◽  
Richard P Nelson ◽  
Seth A Jacobson ◽  
Alessandro Morbidelli
Keyword(s):  
Initial Conditions ◽  
Post Processing ◽  
Significant Modification ◽  
Kepler Mission ◽  
Giant Impacts ◽  
Low Mass ◽  
In Situ Formation ◽  
Dynamical Instabilities ◽  
Gaseous Envelopes

ABSTRACT The NASA’s Kepler mission discovered ∼700 planets in multiplanet systems containing three or more transiting bodies, many of which are super-Earths and mini-Neptunes in compact configurations. Using N-body simulations, we examine the in situ, final stage assembly of multiplanet systems via the collisional accretion of protoplanets. Our initial conditions are constructed using a subset of the Kepler five-planet systems as templates. Two different prescriptions for treating planetary collisions are adopted. The simulations address numerous questions: Do the results depend on the accretion prescription?; do the resulting systems resemble the Kepler systems, and do they reproduce the observed distribution of planetary multiplicities when synthetically observed?; do collisions lead to significant modification of protoplanet compositions, or to stripping of gaseous envelopes?; do the eccentricity distributions agree with those inferred for the Kepler planets? We find that the accretion prescription is unimportant in determining the outcomes. The final planetary systems look broadly similar to the Kepler templates adopted, but the observed distributions of planetary multiplicities or eccentricities are not reproduced, because scattering does not excite the systems sufficiently. In addition, we find that ∼1 per cent of our final systems contain a co-orbital planet pair in horseshoe or tadpole orbits. Post-processing the collision outcomes suggests that they would not significantly change the ice fractions of initially ice-rich protoplanets, but significant stripping of gaseous envelopes appears likely. Hence, it may be difficult to reconcile the observation that many low-mass Kepler planets have H/He envelopes with an in situ formation scenario that involves giant impacts after dispersal of the gas disc.

scholarly journals Method for determining the thermal conductivity of in situ formation rock using drilling cuttings

AIP Advances ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 065015
Author(s):  
Fu Yi ◽  
Xupeng Qi ◽  
Xuexin Zheng ◽  
Huize Yu ◽  
Wenming Bai ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
In Situ Formation
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