scholarly journals Chemical heterogeneities reveal early rapid cooling of Apollo Troctolite 76535

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
William S. Nelson ◽  
Julia E. Hammer ◽  
Thomas Shea ◽  
Eric Hellebrand ◽  
G. Jeffrey Taylor
Keyword(s):  
Lunar Crust ◽  
Magma Body ◽  
Lunar Interior ◽  
Temperature Diffusion ◽  
Melt Infiltration ◽  
History Of ◽  
Feasibility Test ◽  
Reactive Melt Infiltration ◽  
Reactive Melt ◽  
Textural Evidence

AbstractThe evolution of the lunar interior is constrained by samples of the magnesian suite of rocks returned by the Apollo missions. Reconciling the paradoxical geochemical features of this suite constitutes a feasibility test of lunar differentiation models. Here we present the results of a microanalytical examination of the archetypal specimen, troctolite 76535, previously thought to have cooled slowly from a large magma body. We report a degree of intra-crystalline compositional heterogeneity (phosphorus in olivine and sodium in plagioclase) fundamentally inconsistent with prolonged residence at high temperature. Diffusion chronometry shows these heterogeneities could not have survived magmatic temperatures for >~20 My, i.e., far less than the previous estimated cooling duration of >100 My. Quantitative modeling provides a constraint on the thermal history of the lower lunar crust, and the textural evidence of dissolution and reprecipitation in olivine grains supports reactive melt infiltration as the mechanism by which the magnesian suite formed.

scholarly journals W-ZrC composites prepared by reactive melt infiltration of Zr2Cu alloy into binder jet 3D printed WC preforms

2021 ◽  
Vol 94 ◽  
pp. 105411
Author(s):  
Rina K. Mudanyi ◽  
Corson L. Cramer ◽  
Amy M. Elliott ◽  
Kinga A. Unocic ◽  
Qianying Guo ◽  
...  
Keyword(s):  
Melt Infiltration ◽  
3D Printed ◽  
Reactive Melt Infiltration ◽  
Reactive Melt

Preparation of ZrB2 based composites by reactive melt infiltration at relative low temperature

2011 ◽  
Vol 65 (19-20) ◽  
pp. 2910-2912 ◽  
Author(s):  
Shouming Zhang ◽  
Song Wang ◽  
Wei Li ◽  
Yulin Zhu ◽  
Zhaohui Chen
Keyword(s):  
Low Temperature ◽  
Melt Infiltration ◽  
Reactive Melt Infiltration ◽  
Reactive Melt

scholarly journals Fabrication of C/C–SiC–ZrB2 Ultra-High Temperature Composites through Liquid–Solid Chemical Reaction

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1352
Author(s):  
Qian Sun ◽  
Huifeng Zhang ◽  
Chuanbing Huang ◽  
Weigang Zhang
Keyword(s):  
High Temperature ◽  
Ceramic Composites ◽  
Dense Matrix ◽  
Ablation Resistance ◽  
The Matrix ◽  
Melt Infiltration ◽  
Reactive Melt Infiltration ◽  
Reactive Melt ◽  
Diffusion Precipitation ◽  
Ultra High Temperature

In this paper, we aimed to improve the oxidation and ablation resistance of carbon fiber-reinforced carbon (CFC) composites at temperatures above 2000 °C. C/C–SiC–ZrB2 ultra-high temperature ceramic composites were fabricated through a complicated liquid–solid reactive process combining slurry infiltration (SI) and reactive melt infiltration (RMI). A liquid Si–Zr10 eutectic alloy was introduced, at 1600 °C, into porous CFC composites containing two kinds of boride particles (B4C and ZrB2, respectively) to form a SiC–ZrB2 matrix. The effects and mechanism of the introduced B4C and ZrB2 particles on the formation reaction and microstructure of the final C/C–SiC–ZrB2 composites were investigated in detail. It was found that the composite obtained from a C/C–B4C preform displayed a porous and loose structure, and the formed SiC–ZrB2 matrix distributed heterogeneously in the composite due to the asynchronous generation of the SiC and ZrB2 ceramics. However, the C/C–SiC–ZrB2 composite, prepared from a C/C–ZrB2 preform, showed a very dense matrix between the fiber bundles, and elongated plate-like ZrB2 ceramics appeared in the matrix, which were derived from the dissolution–diffusion–precipitation mechanism of the ZrB2 clusters. The latter composite exhibited a relatively higher ZrB2 content (9.51%) and bulk density (2.82 g/cm3), along with lower open porosity (3.43%), which endowed this novel composite with good mechanical properties, including pseudo-plastic fracture behavior.

Microstructure and ablation performance of SiC–ZrC coated C/C composites prepared by reactive melt infiltration

2018 ◽  
Vol 44 (7) ◽  
pp. 8314-8321 ◽  
Author(s):  
Zhe Zhou ◽  
Zexu Sun ◽  
Yicheng Ge ◽  
Ke Peng ◽  
Liping Ran ◽  
...  
Keyword(s):  
Melt Infiltration ◽  
Reactive Melt Infiltration ◽  
Reactive Melt

Reactive Melt Infiltration of Carbon Fiber Reinforced Ceramic Composites for Ultra-High Temperature Applications

2013 ◽  
pp. 323-353
Author(s):  
Bai Shuxin ◽  
Tong Yonggang ◽  
Ye Yicong ◽  
Zhang Hong
Keyword(s):  
High Temperature ◽  
Carbon Fiber ◽  
Chemical Vapor Infiltration ◽  
Future Research ◽  
Fiber Reinforced ◽  
Melt Infiltration ◽  
Carbon Fiber Reinforced ◽  
Reactive Melt Infiltration ◽  
Reactive Melt ◽  
Ultra High Temperature

Carbon fiber reinforced ultra high temperature ceramic matrix composite (C/UHTC) is one of the most promising structural materials capable of prolonged operation in oxidizing environment at ultra high temperatures above 2000 ?C. Reactive melt infiltration (RMI) is a viable processing choice for C/UHTC composite. Compared with chemical vapor infiltration (CVI) and polymer impregnation and pyrolysis (PIP), RMI does not suffer from the drawbacks of time-consuming and high cost. It is viewed as a promising means of achieving near-net shape manufacturing with quick processing time and at low cost. Recently, great efforts have been made on RMI process for C/UHTC composite. Carbon fiber reinforced ZrC, HfC and TiC composites have been successfully fabricated by RMI. The aim of the following chapter is to introduce the RMI process and summarize the progress in RMI process for C/UHTC composite. In addition, future research directions of RMI are also proposed.

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