scholarly journals Strengthening of the Fe-Ni Invar Alloy Through Chromium

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1297 ◽  
Author(s):  
Qingshuang Sui ◽  
Jun He ◽  
Xin Zhang ◽  
Zhonghua Sun ◽  
Yunfei Zhang ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Mechanical Strength ◽  
Aging Time ◽  
Power Transmission ◽  
Coefficient Of Thermal Expansion ◽  
High Strength ◽  
Invar Alloy ◽  
Invar Alloys ◽  
Low Thermal Expansion ◽  
Cost Efficient

Invar alloys with both high strength and low thermal expansion are urgently needed in fields such as overhead power transmission, aero-molds, and so on. In this paper, Cr was introduced as a cost-efficient alloying element into the Fe-36Ni binary invar alloy to increase its mechanical strength. Our results confirmed that fine Cr7C3 precipitants, together with some Fe3C, in the invar alloy aged at 425 °C could be obtained with a short aging time. Those precipitants then grew and aggregated at grain or sub-grain boundaries with an increase in aging time. Simultaneously, mechanical strength and coefficient of thermal expansion (CTE) parabolically varied with the increase in aging time. The sample aged at 425 °C for 7 h presented a maximum strength of 644.4 MPa, together with a minimum coefficient of thermal expansion of 3.30 × 10−6 K−1 in the temperature range of 20–100 °C. This optimized result should be primarily attributed to the precipitation of the nanoscaled Cr7C3.

Impact of Cooling Character on Structure and CTE of Invar Alloy with 0.6%C

2017 ◽  
Vol 265 ◽  
pp. 807-810
Author(s):  
A.S. Zhilin ◽  
S.V. Grachev ◽  
S.M. Nikiforova
Keyword(s):  
Thermal Expansion ◽  
Cooling Rate ◽  
Coefficient Of Thermal Expansion ◽  
Invar Alloy ◽  
Cooling Rates ◽  
Volume Percentage ◽  
Invar Alloys

Metallography analysis of invar alloys crystallized with different cooling rates has been carried out. The study has demonstrated that velocity of crystallization has an impact on the dispersity of graphite. The higher velocity of cooling, the more dispersive graphite is. The volume percentage of graphite in alloy, crystallized with high cooling rate, is lower than compared with low cooling rate. Crystallization with low cooling rate leads to the reduction of the amount of carbon into γ-phase. The coefficient of thermal expansion is basically depends on the amount of carbon into γ-phase.

AlN nanowires for Al-based composites with high strength and low thermal expansion

2007 ◽  
Vol 22 (10) ◽  
pp. 2711-2718 ◽  
Author(s):  
Y.B. Tang ◽  
Y.Q. Liu ◽  
C.H. Sun ◽  
H.T. Cong
Keyword(s):  
Thermal Expansion ◽  
Volume Fraction ◽  
Coefficient Of Thermal Expansion ◽  
Maximum Yield ◽  
High Strength ◽  
Mechanical And Thermal Properties ◽  
Matrix Composites ◽  
Interfacial Reaction Product ◽  
Low Thermal Expansion ◽  
Al Matrix

Based on the synthesis of a sufficient amount of AlN nanowires (AlN-NWs), AlN-NWs/Al composites with homogenously distributed AlN-NWs were fabricated. Microstructural observations reveal that the interface between AlN-NWs and Al matrix is clean and bonded well, and no interfacial reaction product was formed at the nanowire-matrix boundary. Mechanical properties including yield and tensile strength of the composites were improved with AlN-NWs volume fraction changing from 5 to 15 vol%, and the maximum yield and tensile strengths of the composite were about 6 and 5 times, respectively, as high as those of Al matrix. Meanwhile, AlN-NWs effectively decreased the coefficient of thermal expansion (CTE) of the composites, and the CTE of 15 vol% composite was about one half that of Al matrix. The results obtained suggest that AlN nanowire is a promising reinforcement for optimizing the mechanical and thermal properties of metal matrix composites.

β-Spodumene Glass-Ceramic with Anomalous Low Thermal Expansion

2008 ◽  
Vol 39-40 ◽  
pp. 381-386 ◽  
Author(s):  
Akihiko Sakamoto ◽  
Yusuke Himei ◽  
Yoshio Hashibe
Keyword(s):  
Thermal Expansion ◽  
Mechanical Strength ◽  
Ceramic Material ◽  
Glass Ceramic ◽  
Silica Glass ◽  
Coefficient Of Thermal Expansion ◽  
Glass Ceramics ◽  
New Method ◽  
Low Thermal Expansion ◽  
Natural Stones

To survey new method for controlling thermal expansion of glass-ceramic material, we studied the coefficient of thermal expansion (CTE) and the microstructure of β-spodumene glass-ceramics. We found that the CTE of the β-spodumene glass-ceramics is remarkably reduced by introducing interstices at the boundary between the crystalline and glass phases. Despite its relatively low crystallinity (45vol%), a newly developed glass-ceramic showed an anomalous low thermal expansion of 7x10-7 /oC, which compares to that of silica glass. The mechanical strength of this glass-ceramic was at the same level as that of natural stones: marble and granite.

scholarly journals Fe–Ni Invar alloy reinforced by WC nanoparticles with high strength and low thermal expansion

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Shiqi Zheng ◽  
Maximillian Sokoluk ◽  
Gongcheng Yao ◽  
Igor de Rosa ◽  
Xiaochun Li
Keyword(s):  
Thermal Expansion ◽  
High Strength ◽  
Invar Alloy ◽  
Low Thermal Expansion

scholarly journals Impact of Cooling Character on Structure and CTE of Cast Invar Alloy Made From Secondary Raw Materials

2017 ◽  
Vol 2 (2) ◽  
pp. 188
Author(s):  
A.S. Zhilin ◽  
S.V. Grachev ◽  
V.R. Ramazanova ◽  
O. V. Maslova
Keyword(s):  
Thermal Expansion ◽  
Cooling Rate ◽  
Coefficient Of Thermal Expansion ◽  
Raw Materials ◽  
Invar Alloy ◽  
Cooling Rates ◽  
Volume Percentage ◽  
Secondary Raw Materials ◽  
Invar Alloys

<p>Metallography analysis of invar alloys made from secondary raw materials and crystallized with different cooling rates has been carried out. The study has demonstrated that velocity of crystallization has an impact on the dispersity of graphite. The higher velocity of cooling, the more dispersive graphite is. The volume percentage of graphite in alloy, crystallized with high cooling rate, is lower than compared with low cooling rate. Crystallization with low cooling rate leads to the reduction of the amount of carbon into g-phase. The coefficient of thermal expansion is basically depends on the amount of carbon into g-phase.</p>

DELTALLOY 4032

Alloy Digest ◽  
1998 ◽  
Vol 47 (4) ◽  
Keyword(s):  
Wear Resistance ◽  
Thermal Expansion ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Surface Finish ◽  
Coefficient Of Thermal Expansion ◽  
Single Point ◽  
High Strength ◽  
Corrosion And Wear

Abstract Deltalloy 4032 has good machinability and drilling characteristics when using single-point or multispindle screw machines and an excellent surface finish using polycrystalline or carbide tooling. The alloy demonstrates superior wear resistance and may eliminate the need for hard coat anodizing. Deltalloy 4032 is characterized by high strength and a low coefficient of thermal expansion. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion and wear resistance as well as machining and surface treatment. Filing Code: AL-347. Producer or source: ALCOA Wire, Rod & Bar Division.

scholarly journals Fabrication and Characterization of the Modified EV31-Based Metal Matrix Nanocomposites

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 125
Author(s):  
Seyed Kiomars Moheimani ◽  
Mehran Dadkhah ◽  
Mohammad Hossein Mosallanejad ◽  
Abdollah Saboori
Keyword(s):  
Thermal Expansion ◽  
Mechanical Strength ◽  
Metal Matrix ◽  
Coefficient Of Thermal Expansion ◽  
Structural Effect ◽  
Metal Matrix Nanocomposites ◽  
Mechanical Stirring ◽  
Specific Strength ◽  
The Matrix ◽  
Matrix Nanocomposites

Metal matrix nanocomposites (MMNCs) with high specific strength have been of interest for numerous researchers. In the current study, Mg matrix nanocomposites reinforced with AlN nanoparticles were produced using the mechanical stirring-assisted casting method. Microstructure, hardness, physical, thermal and electrical properties of the produced composites were characterized in this work. According to the microstructural evaluations, the ceramic nanoparticles were uniformly dispersed within the matrix by applying a mechanical stirring. At higher AlN contents, however, some agglomerates were observed as a consequence of a particle-pushing mechanism during the solidification. Microhardness results showed a slight improvement in the mechanical strength of the nanocomposites following the addition of AlN nanoparticles. Interestingly, nanocomposite samples were featured with higher electrical and thermal conductivities, which can be attributed to the structural effect of nanoparticles within the matrix. Moreover, thermal expansion analysis of the nanocomposites indicated that the presence of nanoparticles lowered the Coefficient of Thermal Expansion (CTE) in the case of nanocomposites. All in all, this combination of properties, including high mechanical strength, thermal and electrical conductivity, together with low CTE, make these new nanocomposites very promising materials for electro packaging applications.

Thermal Property Evaluation of Chilled Aluminum-Alumina MMC

2015 ◽  
Vol 1101 ◽  
pp. 79-82
Author(s):  
B.C. Suresh ◽  
S.B. Arun
Keyword(s):  
Thermal Expansion ◽  
Composite Materials ◽  
Thermal Property ◽  
Coefficient Of Thermal Expansion ◽  
Matrix Material ◽  
High Strength ◽  
Stir Casting ◽  
Al Alloy ◽  
Industrial Growth ◽  
Property Evaluation

Now a day’s composite materials are taking very important role in industrial growth. Composite materials are widely used in Automobiles, aerospace, submarine and also in other major fields, due to their special characteristics like light weight, high strength, stiffness, corrosion resistance. The determination of Coefficient of Thermal Expansion (CTE) of MMCs is important to aid its usage in high temperature environment as in the case of automobile combustion chamber. In these applications the stability of the composites over a long period of operation is a critical design considerationPresent work deals with the thermal property evaluation of the Al alloy / alumina metal matrix composite developed using the Stir Casting with chilling route technique. LM 26 Al alloy is being selected as the matrix material as it is a potential alloy for automotive piston applications. Al alloy / alumina MMCs was cast under end chilling technique by dispersing the reinforcement from 6 to 12 wt% the steps of 3% to study the variation in its thermal properties. At the same time chill material is also changed (Copper and MS) for different composition of MMCs cast to study the thermal behavior variations. After casting the required MMC, test specimens were prepared as per the standards to conduct thermal conductivity (K) tests and coefficient of thermal expansion (CTE) tests. Above tests were repeated for different composites containing different weight % of dispersed cast using different chills.

Description of the PM Process by Using Ishikawa-Analysis

2013 ◽  
Vol 752 ◽  
pp. 48-56
Author(s):  
Andrea Simon ◽  
Károly Kovács ◽  
C. Hakan Gür ◽  
Tadeusz Pieczonka ◽  
Zoltán Gácsi
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Powder Metallurgy ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
High Strength ◽  
Manufacturing Technology ◽  
Low Density ◽  
Composite Manufacturing ◽  
Low Thermal Expansion

Composites are special material which can provide individual properties such as high strength with low density or good thermal conductivity with low thermal expansion coefficient. Composites conform to the constantly evolving and more complex expectations. In order to make a product with good quality, it is important to choose suitable materials and technology. In this research powder metallurgy (PM), as one of the most common composite manufacturing technology, was examined -which factors and mechanisms influence mostly the properties of the product. Ishikawa method was used to reveal these correlations.

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