scholarly journals Study on the Dissolution and Precipitation Behavior of Self-Designed (NbTi)C Nanoparticles Addition in 1045 Steel

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 184
Author(s):  
Hongwei Zhu ◽  
Haonan Li ◽  
Furen Xiao ◽  
Zhixiang Gao
Keyword(s):  
Tensile Strength ◽  
Electron Microscope ◽  
Optical Microscope ◽  
Cast Steels ◽  
Uniform Dispersion ◽  
The Matrix ◽  
Thermo Calc Software ◽  
Particle Strengthening ◽  
1045 Steel ◽  
Addition Amount

Self-designed (NbTi)C nanoparticles were obtained by mechanical alloying, predispersed in Fe powder, and then added to 1045 steel to obtain modified cast steels. The microstructure of cast steels was investigated by an optical microscope, scanning electron microscope, X-ray diffraction, and a transmission electron microscope. The results showed that (NbTi)C particles can be added to steels and occur in the following forms: original ellipsoidal morphology nanoparticles with uniform dispersion in the matrix, cuboidal nanoparticles in the grain, and microparticles in the grain boundary. Calculations by Thermo-Calc software and solubility formula show that cuboidal (NbTi)C nanoparticles were precipitated in the grain, while the (NbTi)C microparticles were formed by eutectic transformation. The results of the tensile strength of steels show that the strength of modified steels increased and then declined with the increase in the addition amount. When the addition amount was 0.16 wt.%, the modified steel obtained the maximum tensile strength of 759.0 MPa, which is an increase of 52% compared with to that with no addition. The hardness of the modified steel increased with the addition of (NbTi)C nanoparticles. The performance increase was mainly related to grain refinement and the particle strengthening of (NbTi)C nanoparticles, and the performance degradation was related to the increase in eutectic (NbTi)C.

Mechanical Properties and Microstructures of A356 Alloy Prepared by Casting Combined With Forging

2017 ◽  
Author(s):  
Zhenglong Liang ◽  
Qi Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
A356 Alloy ◽  
Optical Microscope ◽  
Micro Hardness ◽  
Forging Process ◽  
Scanning Electron

A novel process which combines casting with forging during one process was proposed to improve mechanical properties and refine microstructure. The microstructure evolution of as-cast samples and forged samples were analyzed by optical microscope and scanning electron microscope (SEM). The tensile properties and micro-hardness were also measured. The results show that combination of casting and forging can improve microstructure and decrease porosity of casting samples, consequently contributing to a better fatigue performance. The ultimate tensile strength and elongation were increased after forging process, however, the yield strength and micro-hardness decreased.

Effect of Mg Addition on the Mechanical Properties of Rapidly Solidified Al-Mn Alloys at Elevated Temperatures

2010 ◽  
Vol 638-642 ◽  
pp. 339-344
Author(s):  
Makoto Sugamata ◽  
Akio Tomioka ◽  
Yousuke Kubota
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Tensile Strength ◽  
Intermetallic Compounds ◽  
Elevated Temperatures ◽  
Optical Microscope ◽  
Strength Increase ◽  
Positive Effects ◽  
Uniform Dispersion ◽  
Rapidly Solidified

With an aim of clarifying the strength of rapidly solidified P/M materials strengthened by solid solution of Mg and dispersion of transition metal compounds at elevated temperature, Al-2mass%Mn, Al-4mass%Mn and Al-6mass%Mn alloys with varied Mg additions of 0, 1 and 3 mass% were prepared by rapid solidification techniques. Rapidly solidified (RS) flakes were produced by remelting alloy ingots in a graphite crucible, atomizing the alloy melt and subsequent splat-quenching on a rotating water-cooled copper roll under argon atmosphere.　The RS flakes were consolidated to the P/M materials by hot extrusion after vacuum degassing. Cast ingots of these alloys were also hot-extruded under the same conditions to the I/M as reference materials. Metallographic structures and constituent phases were studied for the P/M and I/M materials by optical microscope and X-ray diffraction. Mechanical properties of as-extruded and annealed P/M materials and as-extruded I/M materials were examined by tensile test at room and elevated temperatures under various strain rates. Uniform dispersion of fine intermetallic compounds (Al6Mn) was observed in all the as-extruded P/M materials. Added Mg was present as the solute in I/M and P/M materials alloy even after annealing. The P/M materials containing Mg exhibited higher hardness and strength at room temperature, than those without Mg. It was considered that both solid solution of Mg and dispersion of intermetallic compounds were contributing the hardness and strength increase in the rapidly solidified Al-Mn-Mg alloys. Tensile strength increases with increasing amount of Mg in I/M materials at all testing temperatures. However, strength of as-extruded P/M materials decreases with addition of Mg at 573K and 673K. Thus the positive effects of Mg additions on tensile strength of as-extruded P/M materials disappeared at higher testing temperature. Tensile strength of annealed P/M materials in which dislocation density decreased and compound particle coarsened increased with addition of Mg at elevated temperatures.

Experimental Studies on CNT Reinforced Aluminum Matrix Nanocomposites

2015 ◽  
Vol 1101 ◽  
pp. 89-92
Author(s):  
K.V. Sreenivas Rao ◽  
S. Sanman
Keyword(s):  
Carbon Nanotubes ◽  
Tensile Strength ◽  
Carbon Nanotube ◽  
Experimental Studies ◽  
Aluminum Matrix ◽  
Weight Fraction ◽  
Stir Casting ◽  
Aluminum Matrix Composites ◽  
Uniform Dispersion ◽  
The Matrix

The remarkable high tensile strength and very high aspect ratio of carbon nanotubes make them valuable components for mechanically reinforced composite materials. In this study, Carbon Nanotube (CNT) reinforced aluminum matrix composites were prepared by simple stir casting route with different percentages of Carbon Nanotube reinforcement. The prepared nanocomposite specimens were subjected to evaluation of mechanical properties and microstructure. It was evident from the study that, as the weight fraction of nanotube in the matrix increases, the ultimate tensile strength, macro and micro-hardness also increases. The microstructures show clustering of the carbon nanotubes in the matrix. The difficulties experienced in uniform dispersion of Carbon Nanotube in the matrix to achieve optimum desired properties are discussed.

Preparation and Properties of Epoxy Matrix for Composite Cable Core

2011 ◽  
Vol 239-242 ◽  
pp. 2606-2611
Author(s):  
Xian Fu Li ◽  
Lai Chen ◽  
Ting Ting Zeng ◽  
Jia Bao Zhang ◽  
Rui Cheng Bai ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Electron Microscope ◽  
Carbon Fibers ◽  
Main Body ◽  
Curing Agent ◽  
Resin System ◽  
Elongation At Break ◽  
The Matrix ◽  
Heat Deformation ◽  
Scanning Electron

According to the requirements of aluminum conductor composite cores, a kind of resin system was developed with TGDDM as main body, and self-made flexible epoxy SUC-1 as auxiliary, plus methyl hexahydrophthalic anhydride as curing agent. The gel rate of the system was high enough to meet the demands of pultrusion technique. The heat deformation temperature of cured sample reached 194°C, and the tensile strength achieved 62.95Mpa. The elongation at break matched that of carbon fibers. The interfacial bonding between the matrix and the fibers, observed by scanning electron microscope, was tight without debonding phenomenon.

Influence of Microstructure and Precipitates on the Strength of Container Steel

2012 ◽  
Vol 586 ◽  
pp. 225-229
Author(s):  
Jia Yan Ma ◽  
Wen Liang ◽  
Rong Dong Han ◽  
Yun Guan ◽  
Zhao Jun Deng
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Transmission Electron Microscope ◽  
Optical Microscope ◽  
The Other ◽  
Precipitation Strengthening ◽  
Strengthening Effect ◽  
Transmission Electron ◽  
Uniform Dispersion ◽  
Scanning Electron

The variation rules of strength with the microstructure and precipitates of container steel were studied by optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that the microstructures of four kinds of test steels are all bainite and M/A island, but the number and size of islands of M/A and precipitates exist obvious difference: two kinds of test steels have fewer precipitates and more M/A islands, however, the other two kinds of steels are on the contrary. As for the former two kinds steels, the number of M/A islands is larger, and the size is smaller, the strength of steel is higher; For the later two kinds steels, the number of precipitates less than 30nm is larger, and distribution is more uniform dispersion, the strength is higher, precipitation strengthening effect is better. Getting lots of small and uniform M/A islands or precipitates is an effective way of improving the performance of steel.

Effect of Heat Treatment on the Microstructure of Cu-Cr-Zr Alloy

2017 ◽  
Vol 727 ◽  
pp. 166-170 ◽  
Author(s):  
Li Jun Peng ◽  
Hao Feng Xie ◽  
Gao Lei Xu ◽  
Guo Jie Huang ◽  
Zhen Yang
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Volume Fraction ◽  
Homogenization Temperature ◽  
Eutectic Structure ◽  
Optical Microscope ◽  
Heat Treatments ◽  
Transmission Electron ◽  
The Matrix ◽  
Zr Alloy

Effect of Heat treatments on microstructure in a Cu-0.71Cr-0.12Zr alloy (in wt.%) have been investigated. The microstructures are analyzed by optical microscope, scanning electron microscope, transmission electron microscope and high-resolution transmission electron microscope after each step of heat treatments. The results show that the as-cast microstructure of Cu-Cr-Zr alloy is Cu matrix, Cr dendrite and eutectic structure which is composed of Cu and Cu5Zr phase with a fine lamellar structure. By increasing the homogenization temperature or prolonging the holding time, the eutectic structure is dissolved into the matrix gradually and the volume fraction of the Cr phases is obviously reduced. The precipitation of Cr phase prevents from Zr-rich phases dissolving in the matrix. And the proper homogenizing process is 900°C×12 h. When the alloy aged at 450°C for 24 h, the crystallography of Cr precipitates and the orientation relationship between Cr precipitates and Cu matrix is bcc structure and KS-OR, respectively. The disk-shaped precipitate is identified as Cu5Zr phase and their habit plane is parallel to {111}Cu plane.

Analysis of Influencing Factors on Mechanical Properties and Anisotropy of Attapulgite/NR Composites

2010 ◽  
Vol 178 ◽  
pp. 41-46
Author(s):  
Xiao Long Lu ◽  
Qing Guo Tang ◽  
Jin Sheng Liang ◽  
Yan Ding ◽  
Hao Guo
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Rubber Compound ◽  
Short Fibers ◽  
Forming Mechanism ◽  
Modified Attapulgite ◽  
Addition Amount ◽  
Scanning Electron

Based on the dispersion characters of organic modified attapulgite (OAT) short fibers in nature rubber (NR) matrix, this paper analyzed the effects, in terms of addition amount of OAT, processing technology of rubber compound and heat treatment, on mechanical properties and anisotropy of OAT/NR composites. Results indicated that mechanical properties were better when the OAT content is 50 phr and thin-passing is 20 times, meanwhile, the longitudinal and transversal tensile strength of OAT/NR composites were 17.01 0.5 Mpa and 14.18 0.5 Mpa respectively. The anisotropy is obvious. Also the tensile and tear broken section were studied by the scanning electron microscope (SEM) and the forming mechanism of OAT/NR anisotropy composites was discussed.

Influence of Microstructure and Precipitates on the Mechanical Properties of High Strength Hot Strip

2012 ◽  
Vol 538-541 ◽  
pp. 1678-1682
Author(s):  
Jia Yan Ma ◽  
Wen Liang ◽  
Yun Guan ◽  
Zhao Jun Deng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Outer Part ◽  
High Strength ◽  
Optical Microscope ◽  
Middle Part ◽  
Precipitation Strengthening ◽  
Fine Grained ◽  
Hot Strip

The relation between the microstructure, precipitates and the longitudinal mechanical properties of high strength hot strip was studied by optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results showed that the yield strengths of the coil outer and middle parts were higher than that of inner part by 65MPa, and the tensile strength of the coil outer part was higher than that of middle part and inner part by about 50MPa. The number of subgrain with small size and that of dispersion distribution precipitates less than 30nm in outer part and middle part were more than that in inner part, which resulted that subgrain and precipitation strengthening were larger than that of inner part. For the coil inner part, the strengthening effects were made of fine-grained strengthening and M/A islands strengthening. The contribution of subgrain and precipitation strengthening to intensity is larger than that of fine-grained strengthening, which is the main reason causing the outer and middle parts having higher yield strength. The least tensile strength of middle part is related to the many blocky ferrites.

Effect of Hot-Forging on NiTi Shape Memory Alloy Fibers Reinforced Mg Alloy Composite

2007 ◽  
Vol 534-536 ◽  
pp. 873-876
Author(s):  
Qi Guo ◽  
Gang Li ◽  
Jian Ren Tang ◽  
Biao Yan
Keyword(s):  
Plastic Deformation ◽  
Electron Microscope ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Hot Forging ◽  
Optical Microscope ◽  
Mg Alloy ◽  
Niti Shape Memory Alloy ◽  
Alloy Matrix ◽  
The Matrix

The composite used in this paper was prepared by hot-pressing ball-milled Mg alloy powders, in which NiTi shape memory alloy fibers in a row were sandwiched. The microstructure were examined by an optical microscope, scanning electron microscope, X-ray diffraction, and transmission electron microscope to measure its microhardness and density. It is shown that the composite consisted of a homogenous matrix with uniformly distributed NiTi shape memory alloy fibers, where recrystallization took place in the Mg alloy matrix that was subjected to plastic deformation. It is known that plastic deformation is beneficial to the refinement of the grains, that is an adequate bonding forms between the matrix and fibers, the density of the composite increases after the hot-forging; its tensile strength increases significantly because of the grain refinement; the hot-forging process improves the properties of the NiTi shape memory alloy fibers reinforced Mg matrix composite.

The Effect of Ti-Zr Deoxidation on the Mechanical Properties of High Strength Low Alloy Steels

2010 ◽  
Vol 146-147 ◽  
pp. 1878-1884 ◽  
Author(s):  
Wei Yu Lu ◽  
Ling Dong Meng ◽  
Hong Hong Wang ◽  
Dao Yuan Wang ◽  
Yong Kuan Yao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Impact Toughness ◽  
High Strength ◽  
Optical Microscope ◽  
Low Alloy Steels ◽  
X Ray ◽  
The Matrix ◽  
Alloy Steels ◽  
The Stability

The uniformity of the mechanical properties, especially elongation and impact toughness, were compared between steel A, which was deoxidized with Ti-Zr, and steel B, which was deoxidized with Al. Microstructural observations, energy dispersive X-ray spectroscopy and X-ray diffraction analyses were conducted using an optical microscope, a scanning electron microscope and a transmission electron microscope, respectively. Results showed that sub-micron and nano-sized complex oxides were obtained by the combined deoxidation of Ti-Zr. The stability of the mechanical properties of steel A was better than that of steel B. The elongation and impact toughness of steel A were enhanced relative to those of steel B. This was attributed to spheroidization and the dispersed distribution of MnS inclusions in the matrix of steel A.

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