Effects of Vacuum Heat Treatment of Nano Powder on Sintering of Transparent Nano-Crystalline MgAl2O4 Ceramics

2010 ◽  
Vol 434-435 ◽  
pp. 657-660 ◽  
Author(s):  
Xiang Hui Chang ◽  
Duan Wei He ◽  
Jie Zhang ◽  
Yong Tao Zou ◽  
Jiang Hua Wang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Treatment Process ◽  
Nano Particles ◽  
Heat Treatment Process ◽  
Transparent Ceramics ◽  
Vacuum Heat Treatment ◽  
Nano Powder ◽  
Nano Crystalline ◽  
Transmission Electron ◽  
Means Of Transmission

Nano-sized MgAl2O4 powders were treated at 500~1000 oC in a vacuum of 10-3Pa for 2 h, and then sintered at 500~900 oC under 1~6 GPa. The powders with and without vacuum-heat-treatment were investigated by means of Transmission Electron Microscope (TEM) and Sedimentation Test. It was found that the vacuum-heat-treatment of nano powder could effectively get rid of the absorbed gas on the surface of nano-particles. Bulk nanostructured transparent ceramics without cracks were sintered easily with the treated nano-sized powder. The success rate of nano-sinterning of bulk transparent ceramics was greatly increased when a suitable vacuum-heat-treatment process was used for the starting nano-sized powder.

Characterization of Microstructure and Mechanical Properties of a Nb-Microalloyed Steel after Quenching-Partitioning-Tempering Process

2010 ◽  
Vol 654-656 ◽  
pp. 90-93 ◽  
Author(s):  
Xiao Dong Wang ◽  
Zheng Hong Guo ◽  
Yong Hua Rong
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Treatment Process ◽  
Microalloyed Steel ◽  
Heat Treatment Process ◽  
Step Process ◽  
Transmission Electron ◽  
Nb Microalloyed Steel ◽  
Tempering Process

A novel heat treatment process, that is, quenching-partitioning-tempering (Q-P-T) process, has been developed as a new way to obtain ultrahigh strength martensitic structural steel containing retained austenite and alloying carbide. In order to display merit of the Q-P-T process, a medium carbon Nb-microalloyed steel is treated by Q-P-T 1-step process and Q-P-T 2-step process, as well as treated by the transformation induced plasticity heat treatment process and quenching and tempering process, respectively. The results show that Q-P-T samples possess better mechanical properties than those treated by other heat treatment processes. The origin of the good mechanical properties is analyzed based on the phase and microstructure characterization using X-ray diffraction, scanning electron microscopy and transmission electron microscopy.

Effect of Heat Treatment Process on Microstructure and Properties in Low Carbon Si-Mn Q&P Steel

2011 ◽  
Vol 233-235 ◽  
pp. 1009-1013
Author(s):  
Cai Zhao ◽  
Di Tang
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Retained Austenite ◽  
Treatment Process ◽  
Lath Martensite ◽  
Heat Treatment Process ◽  
Low Carbon ◽  
Transmission Electron ◽  
Partitioning Time

The mechanical properties of Low Carbon Si-Mn Q&P steel are strongly affected by the conditions of heat treatment. Microstructures and mechanical properties of Low Carbon Si-Mn Q&P steel at different partitioning temperature and holding time was investigated. The microstructure was analysed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It is shown that the microstructure of Q&P steel is carbon-depleted lath martensite and carbon enriched retained austenite. The retained austenite appear film-type between the laths. Higher partitioning temperature and longer partitioning time can obtain more retained austenite. It is shown that with increasing partitioning time ultimate tensile strength decreases, while elongation increases obviously. Carbon-enriched metastable retained austenite is considered beneficial because the TRIP phenomenon during deformation can contribute to formability and energy absorption.

Study on Kinetics of Vacuum Heat Treatment Process of the Spent Cathode Carbon Blocks from Aluminum Smelters

2020 ◽  
Vol 6 (4) ◽  
pp. 715-723
Author(s):  
Ming-zhuang Xie ◽  
Hong-liang Zhao ◽  
Ze-gang Wu ◽  
Wei Liu ◽  
Rong-bin Li ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Treatment Process ◽  
Heat Treatment Process ◽  
Vacuum Heat Treatment ◽  
Aluminum Smelters ◽  
Cathode Carbon ◽  
Kinetics Of

Effects of Nano Particles on the Microstructure of LM 25 (A356) Alloy Manufactured by Squeeze Casting

2017 ◽  
Vol 867 ◽  
pp. 64-70
Author(s):  
N. Nagendran ◽  
N. Gayathri ◽  
V.K. Shanmuganathan ◽  
S. Praveen
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Treatment Process ◽  
Squeeze Casting ◽  
Casting Process ◽  
Nano Particles ◽  
Heat Treatment Process ◽  
Cast Part ◽  
Heat Treated ◽  
Squeeze Casting Process

Conventional casting process cannot produce parts as strong as forged parts. Also there are chances of many casting defects such as porosity, hot tears, shrinkage, pin holes, blow holes, mould shift flash, slag, short casting, when casting method is used for fabrication. Thus cast parts only have low mechanical properties. Recent trend is to use Squeeze Casting, which results in superior mechanical and casting properties. This technique is a hybrid metal forming process combining features of both casting and forging in one operation. This process is suitable for low melting alloys like iron and nickel with mechanical properties enhancement. Reduction in micro porosity in cast part and also reduction in machining. Historically, the series of LM were developed for high strength, corrosion resistance, and good machinability for many applications. In this study Squeeze Casting process has been used, since it has porosity free equiaxed grain components of LM 25 composition and cylindrical shaped castings were manufactured successfully by squeeze casting machine at high temperature and high pressure. The first part of the study is about the microstructure of the LM 25 Al-7 Si-0.3 Mg-0.5 Fe alloy. The casting products were made by addition of nano particles and without nano particles. The size of bar casted was by squeeze casting process. It was 260 mm*46mm (7 Pieces). Microstructure of Cast without squeeze and without stirrer, without squeeze and with stirrer, with squeeze and with stirrer Alloys was studied. The second part of the work was the heat treatment process of the finished product. Heat treatment process was conducted at 490○C and for the heat treated metals was quenched at 30○C (water) for the heat treated and unheated metal casting product were taken and microstructure were studied. The results were compared before and after the heat treatment process for addition of nano particles and without nano particles.

Optimization of Heat Treatment Process of ZE41A Magnesium Alloy Using Grey- Based Taguchi Method

2008 ◽  
Vol 3 (2) ◽  
pp. 63-69
Author(s):  
M. Sivapragash ◽  
◽  
V. Sateeshkumar ◽  
P.R. Lakshminarayanan ◽  
R. Karthikeyan ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Magnesium Alloy ◽  
Taguchi Method ◽  
Treatment Process ◽  
Heat Treatment Process

EFFECT ON HARDNESS and MICRO STRUCTURAL BEHAVIOUR OF TOOL STEEL AFTER HEAT TREATMENT PROCESS

2017 ◽  
Vol 4 (24) ◽  
Author(s):  
Karanbir Singh ◽  
Aditya Chhabra ◽  
Vaibhav Kapoor ◽  
Vaibhav Kapoor
Keyword(s):  
Heat Treatment ◽  
Empirical Study ◽  
Tool Steel ◽  
Treatment Process ◽  
Heat Treatment Process ◽  
Structural Behaviour ◽  
Treatment Processes ◽  
En 31

This study is conducted to analyze the effect on the Hardness and Micro Structural Behaviour of three Sample Grades of Tool Steel i.e. EN-31, EN-8, and D3 after Heat Treatment Processes Such As Annealing, Normalizing, and Hardening and Tempering. The purpose of Selecting Tool Steel is Because Tool Steel is Mostly Used in the Manufacturing Industry.This study is based upon the empirical study which means it is derived from experiment and observation rather than theory.

Effect of Heat Treatment on Microstructure and Properties of Cu-3Ti-1Al Alloy

2013 ◽  
Vol 749 ◽  
pp. 282-286
Author(s):  
Xian Hui Wang ◽  
Xiao Chun Sun ◽  
Xiao Hong Yang ◽  
Shu Hua Liang
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Electrical Conductivity ◽  
Electron Microscope ◽  
Treatment Process ◽  
Intermetallic Phase ◽  
Strengthening Effect ◽  
Microstructure And Properties ◽  
Optimal Heat Treatment ◽  
Transmission Electron

The effect of heat treatment on the microstructure and properties of Cu-3Ti-1Al alloy was investigated. The microstructure was characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), and the hardness and electrical conductivity were tested as well. The results showed that the hardness and electrical conductivity of Cu-3Ti-1Al alloy increased significantly after solid solution and ageing treatment. The strengthening effect of Cu-3Ti-1Al alloy was attributed to the formation of intermetallic phase such as Ti3Al and fine precipitates of coherent β-Cu4Ti. With increase of the aging time and the temperature, the precipitates became coarse and incoherent with Cu matrix, and the discontinuous precipitate β started to grow from grain boundaries toward grain interior, which decreased hardness. As the formation of Ti3Al, β-Cu3Ti and β-Cu4Ti phase can efficiently reduce Ti concentration in Cu matrix. The electrical conductivity of Cu-3Ti-1Al alloy increases. In the range of experiments, the optimal heat treatment process for Cu-3Ti-1Al alloy is solid solution at 850°C for 4h and ageing 500°C for 2h, and the hardness and electrical conductivity are 227HV and 12.3%IACS, respectively.

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