NiAl Matrix Self-Lubricating Composite at a Wide Temperature Range

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Shengyu Zhu ◽  
Lingqian Kong ◽  
Fei Li ◽  
Jun Yang ◽  
Jiqiang Ma ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Powder Metallurgy ◽  
Synergistic Effect ◽  
Wide Temperature Range ◽  
Room Temperature ◽  
Friction Reduction ◽  
Powder Metallurgy Technique ◽  
Temperature Range ◽  
Nial Matrix ◽  
Lubricating Properties

Self-lubricating composite NiAl–Cr–Mo–CaF2–Ag was fabricated by powder metallurgy technique. The NiAl matrix composite with 10 wt.% Ag provides self-lubricating properties at a broad temperature range between room temperature and 1000 °C. Especially at 800 °C, the composite offers excellent friction reduction about 0.2 and wear resistance about 0.7 × 10−4 mm3 N−1 m−1. The lubricous behavior at a wide temperature range could be attributed to the synergistic effect of Ag, CaF2, CaCrO4, and CaMoO4.

High Temperature Lubricating Behavior of NiAl Matrix Composites With Addition of CuO

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Shengyu Zhu ◽  
Jun Cheng ◽  
Zhuhui Qiao ◽  
Yuan Tian ◽  
Jun Yang
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Powder Metallurgy ◽  
Friction Coefficient ◽  
High Temperatures ◽  
Room Temperature ◽  
Tribological Behavior ◽  
Matrix Composites ◽  
Powder Metallurgy Technique ◽  
Nial Matrix

High temperature self-lubricating NiAl matrix composites with addition of CuO (15, 20, and 25 wt.%) were fabricated by powder metallurgy technique, and the tribological behavior from room temperature to 1000 °C was investigated. It was found that Ni–Cu and Al2O3 phases formed during the fabrication process due to reaction of NiAl and CuO. The tribological results showed that the composite with addition of 25 wt.% CuO has a favorable friction coefficient of about 0.2 and excellent wear resistance with the magnitude of 10−6 mm3 N−1 m−1 at high temperatures (800 and 1000 °C).

An alkali metal–selenium battery with a wide temperature range and low self-discharge

2019 ◽  
Vol 7 (38) ◽  
pp. 21774-21782 ◽  
Author(s):  
Xiaosen Zhao ◽  
Lichang Yin ◽  
Zhenzhen Yang ◽  
Gang Chen ◽  
Huijuan Yue ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Alkali Metal ◽  
Wide Temperature Range ◽  
High Performance ◽  
Temperature Range

A high performance alkali metal–selenium battery with a wide temperature range was obtained by the synergistic effect of microporous fixation and heteroatom adsorption.

Preparation of Cu-Cr-Zr/AlN Nanocomposites and their Mechanical and Conductive Properties

2011 ◽  
Vol 239-242 ◽  
pp. 2756-2759
Author(s):  
Yong Qiang Qin ◽  
Yu Cheng Wu ◽  
Yan Wang ◽  
Yu Hong ◽  
Jing Quan Deng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Wear Resistance ◽  
High Temperature ◽  
Powder Metallurgy ◽  
Mechanical Alloying ◽  
Room Temperature ◽  
Copper Alloys ◽  
Morphology Characterization ◽  
Conductive Properties ◽  
Conductivity Behavior

Copper and copper alloys had various applications in tremendous areas due to their unique properties, such as good conductivity, good thermal conductivity and so on. However, applications of copper and copper alloys were severely restricted as the result of the limited strength at room temperature and poor wear-resistance at high temperature. In this paper, we investigated the preparation of Cu-Cr-Zr/AlN nanocomposites by mechanical alloying process and then powder metallurgy technology. XRD and SEM were performed for the phase and morphology characterization. The conductivity properties were also tested and the results showed that Cu-Cr-Zr/AlN nanocomposites exhibited excellent conductivity behavior.

scholarly journals Phonon hydrodynamics and ultrahigh–room-temperature thermal conductivity in thin graphite

Science ◽  
2020 ◽  
Vol 367 (6475) ◽  
pp. 309-312 ◽  
Author(s):  
Yo Machida ◽  
Nayuta Matsumoto ◽  
Takayuki Isono ◽  
Kamran Behnia
Keyword(s):  
Thermal Conductivity ◽  
Thermal Diffusivity ◽  
Wide Temperature Range ◽  
Room Temperature ◽  
Phonon Dispersion ◽  
High Conductivity ◽  
Temperature Range ◽  
A Value ◽  
Out Of Plane ◽  
Intimate Link

Allotropes of carbon, such as diamond and graphene, are among the best conductors of heat. We monitored the evolution of thermal conductivity in thin graphite as a function of temperature and thickness and found an intimate link between high conductivity, thickness, and phonon hydrodynamics. The room-temperature in-plane thermal conductivity of 8.5-micrometer-thick graphite was 4300 watts per meter-kelvin—a value well above that for diamond and slightly larger than in isotopically purified graphene. Warming enhances thermal diffusivity across a wide temperature range, supporting partially hydrodynamic phonon flow. The enhancement of thermal conductivity that we observed with decreasing thickness points to a correlation between the out-of-plane momentum of phonons and the fraction of momentum-relaxing collisions. We argue that this is due to the extreme phonon dispersion anisotropy in graphite.

scholarly journals Wide-Gap Brazing of K417G Alloy Assisted by In Situ Precipitation of M3B2 Boride Particles

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3140 ◽  
Author(s):  
Zhun Cheng ◽  
Xiaoqiang Li ◽  
Minai Zhang ◽  
Shengguan Qu ◽  
Huiyun Li
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Room Temperature ◽  
Distribution Characteristics ◽  
Powder Metallurgy Technique ◽  
Dispersion Strengthening ◽  
Eutectic Transformation ◽  
Wide Gap ◽  
Strength And Plasticity

In this study, K417G Ni-based superalloy with a 20-mm gap was successfully bonded at 1200 °C using powder metallurgy with a powder mixture. The results indicated that the microstructure and mechanical properties of the as-bonded alloy were highly dependent on the brazing time (15–45 min), mainly due to the precipitation and distribution characteristics of M3B2 boride particles. Specifically, alloy brazed for 30 min exhibited desirable mechanical properties, such as a high tensile ultimate strength of 971 MPa and an elongation at fracture of 6.5% at room temperature, exceeding the balance value (935 MPa) of the base metal. The excellent strength and plasticity were mainly due to coherent strengthening and dispersion strengthening of the in situ spherical and equiaxed M3B2 boride particles in the γ + γ′ matrix. In addition, the disappearance of dendrites and the homogenization of the microstructure are other factors that cannot be excluded. This powder metallurgy technique, which can avoid the eutectic transformation of traditional brazing, provides a new effective method for wide-gap repair of alloy materials.

Fast kinetics of Mg2+/Li+ hybrid ions in a polyanion Li3V2(PO4)3 cathode in a wide temperature range

2019 ◽  
Vol 7 (16) ◽  
pp. 9968-9976 ◽  
Author(s):  
Muhammad Rashad ◽  
Hongzhang Zhang ◽  
Xianfeng Li ◽  
Huamin Zhang
Keyword(s):  
Wide Temperature Range ◽  
Low Temperatures ◽  
Room Temperature ◽  
Excellent Performance ◽  
Fast Kinetics ◽  
Temperature Range ◽  
Kinetics Of

A Li3V2(PO4)3 based Mg2+/Li+ hybrid battery with excellent performance both at room temperature and low temperatures (0, −10, −20, −30, and −40 °C) is presented.

The tunable negative thermal expansion covering a wide temperature range around room temperature in Sn, Mn co-substituted Mn3ZnN

2020 ◽  
Vol 49 (30) ◽  
pp. 10407-10412
Author(s):  
Shugang Tan ◽  
Chenhao Gao ◽  
Cao Wang ◽  
Tong Zhou ◽  
Guangchao Yin ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Wide Temperature Range ◽  
Room Temperature ◽  
Negative Thermal Expansion ◽  
Temperature Range

Based on anti-perovskite Mn3ZnN, the negative thermal expansion (NTE) temperature can be effectively broadened via co-substituting Sn, Mn.

PEEK- and PTFE- Based Composites for Tribology Applications in a Range between Liquid Helium and Room Temperature

2007 ◽  
Vol 334-335 ◽  
pp. 597-600
Author(s):  
Klaus Friedrich ◽  
Patrick Klein ◽  
Geraldine Theiler ◽  
Lin Ye ◽  
Yiu Wing Mai
Keyword(s):  
Wear Resistance ◽  
Carbon Fibers ◽  
Wide Temperature Range ◽  
Room Temperature ◽  
Extreme Environments ◽  
Short Fiber ◽  
Low Friction ◽  
Wear Performance ◽  
Polymer Component ◽  
Low Wear

This study deals with the development of PEEK (polyetheretherketone) and PTFE (polytetrafluoroethylene) based composites, optimized for low friction and low wear performance under extreme environments. It is demonstrated that the incorporation of a harder polymer component into PTFE (such as PEEK particles), a short fiber reinforcement (e.g. carbon fibers CF), and internal lubricants (e.g. PTFE particles), helps to reduce the friction and to improve the wear resistance over a very wide temperature range.

Sign in / Sign up

Export Citation Format

Share Document