Effects of Heat Treatment on Strength Wear Sintered Alloy Steels

2015 ◽  
Vol 1128 ◽  
pp. 315-321
Author(s):  
Ionela Gabriela Bucse ◽  
Olimpia Ghermec ◽  
Mariana Ciobanu ◽  
Christian Ghermec ◽  
Claudiu Nicolicescu
Keyword(s):  
Heat Treatment ◽  
Mechanical Alloying ◽  
Room Temperature ◽  
Structural Characteristics ◽  
Sintered Alloy ◽  
Sintering Process ◽  
Wear Coefficient ◽  
Sintered Steels ◽  
Alloy Steels ◽  
Size Powder

This paper presents the results of experimental research on thermal treatment of alloyed sintered steels and much the development of Fe‒3Mn‒1Mo‒1.5Cr‒0.5B‒0.45Graphite powder using mechanical alloying (MA). It was analyzed the influence of MA time on the morphology of the compound by electron microscopy SEM. The research has followed the study of the particle size powder mixtures influence obtained by mechanical alloying, compaction parameters and sintering process on the chemical and structural characteristics of the alloyed sintered steels. Thus there were compacted samples at 600, 700 and 800 MPa. The samples were heated using argon at a temperature of 1150°C using 60 minutes as a maintaining time. Cooling to the room temperature was achieved using a speed of about 30°C/ minutes. With the resulting steels, we have made metallographic determinations using optic microscopy and determinations of the main mechanical properties. Heat treatment took place (heating at 960°C and cooling in the H2O solution and 10% NaCl) in order to improve the properties of alloyed sintered steel hardness and strength. Specimens quenched and tempered have high wear coefficient compared with specimens as-sintered.

Investigation of Microstructure and Property of Fe3Al/Al2O3 Composites

2010 ◽  
Vol 150-151 ◽  
pp. 1409-1412 ◽  
Author(s):  
Tao Jiang
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Mechanical Alloying ◽  
Sintering Process ◽  
Composite Powders ◽  
Al2o3 Composite ◽  
Al2o3 Phase ◽  
The Mean ◽  
Xrd Patterns ◽  
Al2o3 Matrix

The Fe3Al/Al2O3 composites were fabricated by pressureless sintering process. The Fe3Al intermetallics compounds powders were fabricated by mechanical alloying and heat treatment, then the Fe3Al powders and Al2O3 powders were mixed and the Fe3Al/Al2O3 composite powders were prepared, so the Fe3Al/Al2O3 composites were fabricated by sintering process at 1700oC for 2h. The phase composition and microstructure of Fe3Al intermetallics compounds powders produced by mechanical alloying and heat treatment were investigated. The phase composition, microstructure and mechanical properties of the Fe3Al/Al2O3 composites sintered bulks were investigated. The XRD patterns results showed that there existed Fe3Al phase and Al2O3 phase in the sintered composites. The Fe3Al/Al2O3 composites sintered bulks exhibited the homogenous and compact microstructure, the Fe3Al particles were homogenously distributed in the Al2O3 matrix, the mean particles size of Fe3Al intermetallics was about 3-5μm. The Fe3Al/Al2O3 composites exhibited more homogenous and compact microstructure with the increase of Fe3Al content in the Al2O3 matrix. The density and relative density of the Fe3Al/Al2O3 composites increased gradually with the increase of Fe3Al content. The fracture strength and fracture toughness of the Fe3Al/Al2O3 composites increased gradually with the increase of Fe3Al content. The elastic modulus and hardness (HRA) of the Fe3Al/Al2O3 composites decreased gradually with the increase of Fe3Al content.

Investigation of Microstructure and Property of the Fe3Al/Al2O3 Composites Fabricated by Mechanical Alloying Process and Plasma Active Sintering Process

2011 ◽  
Vol 194-196 ◽  
pp. 1689-1692
Author(s):  
Tao Jiang
Keyword(s):  
Heat Treatment ◽  
Mechanical Property ◽  
Phase Composition ◽  
Mechanical Alloying ◽  
Sintering Process ◽  
Composite Powders ◽  
Al Content ◽  
The Mean ◽  
Xrd Patterns ◽  
Microstructure And Mechanical Property

The Fe3Al/Al2O3composites were fabricated by plasma active sintering process. The Fe3Al intermetallics compounds powders were fabricated by mechanical alloying and heat treatment, then the Fe3Al powders and Al2O3powders were mixed and the Fe3Al/Al2O3composite powders were prepared, so the Fe3Al/Al2O3composites were fabricated by plasma active sintering process at 1200°C for 5min under the pressure of 30MPa. The phase composition and microstructure of the Fe3Al intermetallics compounds powders produced by mechanical alloying and heat treatment were investigated. The phase composition, microstructure and mechanical property of the Fe3Al/Al2O3composites sintered bulks were investigated. The XRD patterns results showed that there existed Fe3Al phase and Al2O3phase in the sintered composites. The Fe3Al/Al2O3composites sintered bulks exhibited the homogenous and compact microstructure, the Fe3Al particles were homogenously distributed in the Al2O3matrix. The mean particles size of Fe3Al intermetallics was about 2-3μm and mean particles sizes of Al2O3was about 2-3μm. The density and relative density of the Fe3Al/Al2O3composites increased gradually with the increase of Fe3Al content. The fracture strength and fracture toughness of the Fe3Al/Al2O3composites increased gradually with the increase of Fe3Al content. The elastic modulus and hardness(HRA) of Fe3Al/Al2O3composites decreased gradually with the increase of Fe3Al content.

Fabrication and Microstructure of the Fe3Al/Al2O3 Composites by Pressureless Sintering

2010 ◽  
Vol 177 ◽  
pp. 411-414
Author(s):  
Tao Jiang ◽  
Ke Wei Pan
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Mechanical Alloying ◽  
Pressureless Sintering ◽  
Sintering Process ◽  
Al2o3 Phase ◽  
The Mean ◽  
Xrd Patterns ◽  
Al2o3 Matrix

Fe3Al/Al2O3 composites were fabricated by pressureless sintering in this research. Fe3Al intermetallics compounds powders were fabricated by mechanical alloying and heat treatment. The Fe3Al powders and Al2O3 powders were mixed together, then the Fe3Al/Al2O3 composites were fabricated by pressureless sintering process at 1700oC for 2h. The phase composition and microstructure of the Fe3Al intermetallics compounds powders and the phase composition and microstructure of the sintered Fe3Al/Al2O3 composites were investigated. The XRD patterns results showed that the Fe-Al intermetallics compounds powders were prepared by mechanical alloying for 60h, and the Fe-Al intermetallics compounds powders transformed into Fe3Al intermetallics compounds powders after heat treatment at 800oC and 1000oC. The XRD patterns results showed that there existed Fe3Al phase and Al2O3 phase in the sintered composites. The microstructure showed that the mean particles size of the Fe3Al intermetallics compounds powders produced by mechanical alloying and heat treatment was rather fine and about 2-3μm. The sintered Fe3Al/Al2O3 composites exhibited homogenous and compact microstructure, the Fe3Al particles were homogenously distributed in the Al2O3 matrix. The mean particles size of Fe3Al was about 3-5μm. The sintered Fe3Al/Al2O3 composites exhibited more homogenous and compact microstructure with the increase of Fe3Al content in the Al2O3 matrix.

Thermoelectric Properties of Bi2Te3-Sb2Te3 Compounds Prepared by Ma-Pulse Discharge Sintering Process

1999 ◽  
Vol 581 ◽  
Author(s):  
R.E. Park ◽  
Y.H. Park ◽  
T. Abe
Keyword(s):  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Mechanical Alloying ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Pulse Discharge ◽  
Sintering Process ◽  
Mechanically Alloyed ◽  
Fine Grain ◽  
Process Effects

ABSTRACTThe Bi2Te3-Sb2Te3 compounds with the composition of useful thermoelectric cooling materials were prepared by mechanical alloying-pulse discharge sintering process. Effects of the process on the Seebeck coefficient, electrical resistivity and thermal conductivity were investigated. Temperature dependence of the Hall coefficient was also observed in the temperature range 80 - 325 K.The figure of merit, Z, was found to be about 4.0 × 10−1K−1 at room temperature in the 25%Bi2Te3-75%Sb2Te3 composition sintered at 618K using grain refined mechanically alloyed powders which had the size of under 32 μm. The value of Z was remarkably improved with a decrease of the thermal conductivity shown in the fine grain compacts fabricated by mechanical alloying-pulse discharge sintering process.

scholarly journals New alloying systems for ferrous powder metallurgy precision parts

2008 ◽  
Vol 40 (1) ◽  
pp. 33-46 ◽  
Author(s):  
H. Danninger ◽  
C. Gierl
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Chemical Reactions ◽  
Sintering Process ◽  
Critical Importance ◽  
Sintered Steels ◽  
Alloy Steels ◽  
The Common

Traditionally, the common alloy elements for sintered steels have been Cu and Ni. With increasing requirements towards mechanical properties, and also as a consequence of soaring prices especially for these two metals, other alloy elements have also become more and more attractive for sintered steels, which make the steels however more tricky to process through PM. Here, the chances and risks of using in particular Cr and Mn alloy steels are discussed, considering the different alloying techniques viable in powder metallurgy, and it is shown that there are specific requirements in particular for sintering process. The critical importance of chemical reactions between the metal and the atmosphere is described, and it is shown that not only O2 and H2O but also H2 and even N2 can critically affect sintering and microstructural homogenization.

scholarly journals New alloying systems for ferrous powder metallurgy precision parts

2008 ◽  
Vol 40 (1) ◽  
pp. 33-46
Author(s):  
H. Danninger ◽  
C. Gierl
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Chemical Reactions ◽  
Sintering Process ◽  
Critical Importance ◽  
Sintered Steels ◽  
Alloy Steels ◽  
The Common

Traditionally, the common alloy elements for sintered steels have been Cu and Ni. With increasing requirements towards mechanical properties, and also as a consequence of soaring prices especially for these two metals, other alloy elements have also become more and more attractive for sintered steels, which make the steels however more tricky to process through PM. Here, the chances and risks of using in particular Cr and Mn alloy steels are discussed, considering the different alloying techniques viable in powder metallurgy, and it is shown that there are specific requirements in particular for sintering process. The critical importance of chemical reactions between the metal and the atmosphere is described, and it is shown that not only O2 and H2O but also H2 and even N2 can critically affect sintering and microstructural homogenization.

Fabrication of Mg2Si Thermoelectric Materials by Mechanical Alloying and Spark-Plasma Sintering Process

2006 ◽  
Vol 6 (11) ◽  
pp. 3429-3432
Author(s):  
Chung-Hyo Lee ◽  
Seong-Hee Lee ◽  
Sung-Yong Chun ◽  
Sang-Jin Lee
Keyword(s):  
Grain Size ◽  
Mechanical Alloying ◽  
Spark Plasma Sintering ◽  
Room Temperature ◽  
Atomic Ratio ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Sintering ◽  
Spark Plasma

A mixture of pure Mg and Si powders with an atomic ratio 2:1 has been subjected to mechanical alloying (MA) at room temperature to prepare the Mg2Si thermoelectric material. Mg2Si intermetallic compound with a grain size of 50 nm can be obtained by MA of Mg66.7Si33.3 powders for 60 hours and subsequently annealed at 620 °C. Consolidation of the MA powders was performed in a spark plasma sintering (SPS) machine using graphite dies up to 800–900 °C under 50 MPa. The shrinkage of consolidated samples during SPS was significant at about 250 °C and 620 °C. X-ray diffraction data shows that the SPS compact from 60 h MA powders consolidated up to 800 °C consists of only nanocrystalline Mg2Si compound with a grain size of 100 nm.

Order Effect of Vacuum and Ammonia Atmospheres on Aluminium Nitriding by Mechanical Alloying

2012 ◽  
Vol 730-732 ◽  
pp. 936-941 ◽  
Author(s):  
Eduardo Sánchez Caballero ◽  
J. Cintas ◽  
M. Herrera-García ◽  
Francicso Gomez Cuevas ◽  
Juan M. Montes
Keyword(s):  
Heat Treatment ◽  
Mechanical Alloying ◽  
Room Temperature ◽  
Order Effect ◽  
Milling Process ◽  
Subsequent Heat Treatment ◽  
Aluminium Powder ◽  
Xrd Study ◽  
Aluminium Lattice

Aluminium powder was milled under vacuum and/or ammonia atmospheres, in order to evaluate the effect of the order of the atmospheres on the amount of nitrides appearing in the powder after a subsequent heat treatment. All milling experiences were carried out at room temperature for 5 h. The XRD study of sintered powders showed that important amounts of AlN appeared after heating. The use of vacuum and ammonia flow allows controlling the percentage of N rich phases formed. Moreover, the capacity of incorporating nitrogen to the aluminium lattice is very influenced by the vacuum and ammonia flow atmospheres order during the milling process.

Investigation of Phase Composition and Microstructure of the FeAl/Al2O3 Composites Fabricated by Mechanical Alloying Process and Pressureless Sintering Process

2011 ◽  
Vol 239-242 ◽  
pp. 968-971
Author(s):  
Tao Jiang
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Mechanical Alloying ◽  
Treatment Process ◽  
Pressureless Sintering ◽  
Heat Treatment Process ◽  
Sintering Process ◽  
Composite Powders ◽  
The Mean ◽  
Xrd Patterns

The FeAl/Al2O3composites were fabricated by pressureless sintering process. The FeAl intermetallics compounds powders were fabricated by mechanical alloying and heat treatment process. The FeAl intermetallics compounds powders and Al2O3powders were mixed and the FeAl/Al2O3composite powders were prepared. The FeAl/Al2O3composites bulks were fabricated by pressureless sintering process at 1600°C for 2h. The phase composition and microstructure of FeAl intermetallics compounds powders produced by mechanical alloying and heat treatment were investigated. The phase composition and microstructure of the FeAl/Al2O3composites sintered bulks were investigated. The XRD patterns results showed that the Fe-Al intermetallics compounds powders were fabricated by mechanical alloying for 60h. The FeAl intermetallics compounds powders were fabricated by heat treatment at 800°C, 900°C and 1000°C. The microstructure showed that the mean particles size of the FeAl intermetallics compounds powders produced by mechanical alloying and heat treatment process was rather fine and about 4-5μm. The XRD patterns results showed that there existed the FeAl phase and Al2O3phase in sintered composites. The FeAl/Al2O3composites bulks exhibited the homogenous and compact microstructure. The mean particles size of FeAl was about 4-5μm and the mean particles size of Al2O3was about 5-10μm. The density and relative density of the FeAl/Al2O3composites increased gradually with the increase of FeAl content.

Tribological Behavior of Distaloy DC Components

2017 ◽  
Vol 907 ◽  
pp. 121-125
Author(s):  
Kerim Emre Öksüz ◽  
Yusuf Alper Akınalp ◽  
Levent Cenk Kumruoğlu
Keyword(s):  
Automotive Industry ◽  
Room Temperature ◽  
Sintered Material ◽  
Tribological Behavior ◽  
High Strength ◽  
Raw Material ◽  
Sintered Alloy ◽  
Sintering Process ◽  
Machine Parts ◽  
Powder Type

A sintered material based on pre-alloyed powders (Fe-Ni-Mo) is expansively applied in the automotive industry and Distaloy is today the most widely used raw material worldwide for the production of complex, precise, high strength PM machine parts. In this study a diffusion bonded powder type of Distaloy DC (Fe-2 wt. % Ni-1.5 wt. % Mo, Höganäs-Sweden) was used. It was alloyed by 0.5 and 1 wt. % silicon carbide with the addition of 0.6 wt. % lubricant in the form of introlube®. All the powder mixtures were compacted at 600 MPa, and then sintered for 30 min. in argon atmosphere at 1120° C. After the completed sintering process, the sintered alloy samples were gas-nitrided 1h at 490 °C and 6h at 540 °C, respectively, and cooled slowly to room temperature still under the ammonia atmosphere. The effects of varied amounts of SiC particles on the tribological behavior of nitrided-sintered Distaloy DC composites were investigated.

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