Correlation between Microstructure and Properties of Semi-Solid Products

2019 ◽  
Vol 285 ◽  
pp. 12-23 ◽  
Author(s):  
Annalisa Pola
Keyword(s):  
Mechanical Properties ◽  
Fatigue Wear ◽  
Microstructure And Properties ◽  
Tensile Fatigue ◽  
Wear And Corrosion ◽  
Semi Solid ◽  
Wear And Corrosion Resistance ◽  
Permanent Mold Castings ◽  
The Relationship ◽  
Better Than

Since the very first production trials, it was evident that semi-solid components exhibit excellent mechanical properties, comparable to those of forged material and, in any case, better than permanent mold castings. Over the years, these findings have been confirmed by many authors. Most of the papers available in scientific literature deals with the demonstration of this improvement, especially in order to show the reliability of new and alternative production routes. On the contrary, only some studies focus their attention on the relationship between enhanced mechanical properties and the microstructure. However, it is demonstrated that the increased performance of semi-solid components is not only due to the absence of porosity, but there is a clear relationship between microstructure and properties. This paper reports about the state of knowledge in this subject, in particular for what concerns tensile, fatigue, wear and corrosion resistance.

Effect of Holding Time on Microstructure and Properties of VC/Fe Composite

2012 ◽  
Vol 723 ◽  
pp. 353-357
Author(s):  
Guo Jun Zhang ◽  
Zhi Ping Sun ◽  
Li Yan Zou
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Relative Density ◽  
Bending Strength ◽  
Holding Time ◽  
Microstructure And Properties ◽  
Microstructure And Mechanical Properties ◽  
Relationship Of ◽  
The Relationship ◽  
Better Than

The microstructure and mechanical properties of samples were examined, and the relationship of structure and mechanical properties for VC/Fe composite sintered at different holding time were studied. Holding time can influence the mechanical properties, with the holding time rising, when the holding time is 80 min, the hardness is Max, it’s 10.71 GPa, the enhancing range is 37.66%; The relative density changes slower from 60 to 100 min; when the holding time is 60 minutes, fracture toughness and bending strength of material is 16.17 MPa•m 1/2 and 1070 MPa, it’s better than before.

Microstructure and Properties of WC-CO-Cr Coatings

1996 ◽  
Author(s):  
L.-M. Berger ◽  
P. Vuoristo ◽  
T. Mäntylä ◽  
W. Kunert ◽  
W. Lengauer ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Practical Importance ◽  
Wear Test ◽  
Wear Behaviour ◽  
Metallic Binder ◽  
Microstructure And Properties ◽  
Wear And Corrosion ◽  
Number Of Publications ◽  
Wear And Corrosion Resistance

Abstract WC-Co-Cr represents an important composition for hardmetal-like coatings which is appHed when simuhaneous wear and corrosion resistance is required. In this paper five commercially available spray powders obtained by various production techniques (sintered and crushed as well as agglomerated and plasma-densified) of the composition WC-10%Co- 4%Cr have been thoroughly characterized and were sprayed by DCS, HVOF (CDS process) and APS. The microstructures of the coatings were characterized and their wear behaviour was investigated by means of an abrasion wear test. For the best of these powders the wear resistance was nearly equal for the DGS and HVOF coatings. Other powders show significant differences with respect to their processabilities in these spray processes. APS coatings from all powders, obtained with an Ar/H2 plasma showed inferior microstructures and significant lower wear resistance. The spray powder compositions, grain sizes and structures were found to determine the processability of the powders and the microstructure and properties of the coatings. COMPOSITE MATERIALS of the type hard phase - metallic binder with WC and CoCr as constituents are widely used for the preparation of hardmetal-like coatings. The chromium addition to the metallic binder is thought to improve its corrosion resistance in comparison with pure WC-Co. This has led to many applications of WC-CoCr coatings where simultaneous wear and corrosion resistance is required. Despite of its significant practical importance only a limited number of publications is devoted to detailed questions of structure and properties of WC-CoCr coatings (1-3). In some comparative studies such coatings have been investigated together with WC-Co and Cr3C2-NiCr coatings (4-8). However, systematic investigations of spray powder compositions and morphologies as well as investigations of the influence of different thermal spray processes on coating structures and properties which have repeatedly been provided for WC-Co (for example (9, 10)) are missing for WC-CoCr. In this paper a short survey of literature on the phase relationships in the WC-CoCr system and the effect of chromium additions on the properties of sintered parts and thermally sprayed coatings compared to WC-Co is given. In the experimental part a systematic study of the influence of the preparation process on composition and morphology of commercially available WC-10%Co-4%Cr spray powders was provided. These powders have been sprayed by DGS, HVOF and APS and the microstructure and basic properties of the coatings have been studied.

Effects of Sintering Process on the Properties of Ti3SiC2/Cu Composite

2012 ◽  
Vol 512-515 ◽  
pp. 377-381 ◽  
Author(s):  
Jin Rong Lu ◽  
Yang Zhou ◽  
Yong Zheng ◽  
Shi Bo Li ◽  
Zhen Ying Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Sintering Temperature ◽  
Sintering Process ◽  
Vacuum Sintering ◽  
New Type ◽  
Sintering Conditions ◽  
The Relationship ◽  
Better Than

In this paper, a new type of Ti3SiC2/Cu composites with the volume fractions of 30% Ti3SiC2 particle was prepared by hot pressing and vacuum sintering respectively. The effects of sintering temperature and holding time on the density, resistance and Vickers hardness of Cu-30vol%Ti3SiC2 composite were investigated. The results show that the mechanical properties of the composites prepared by hot pressing are better than that prepared by vacuum sintering. The relative densities of Cu-30vol% Ti3SiC2 composites are rather high in suitable sintering conditions. It achieved 100% for the composites prepared by hot pressing at 930°C for 2h, and 98.4% for the composites prepared by vacuum sintering at 1250°C for 1h. At the same time, the maximum Vickers hardness reached 1735MPa at 900°C by hot pressing. The resistance and Vickers hardness of the composites decreased with an increase in sintering temperature, whereas the density increased. Scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS) were used to observe the microstructure of the composites. The relationship between microstructure and mechanical properties was discussed.

Effect of Sintering Temperature on Microstructure and Properties of VС/Fe Composite

2012 ◽  
Vol 430-432 ◽  
pp. 978-983
Author(s):  
Guo Jun Zhang ◽  
Zhi Ping Sun ◽  
Li Yan Zou
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Sintering Temperature ◽  
Growth Trend ◽  
Flexure Strength ◽  
Microstructure And Properties ◽  
Whole Process ◽  
Relationship Of ◽  
The Relationship ◽  
Composite Samples

VC/Fe composite samples were fabricated by sintering at 1050, 1100 and 1150°C in vacuum. The microstructure and mechanical properties of samples were examined, and the relationship of structure and mechanical properties for VC/Fe composite sintered at different temperature were studied. The results show that fracture toughness, hardness and density is increasing obviously at 1050-1100°Cwith the increasing sintering temperature, but the growth trend increases slowly at 1100-1150°C; in whole process with temperature increased, Flexure strength heighten trend obviously. The microstructure of VC/Fe composite changed from particles piled up together to the microstructure particles closely, VC particles set gradually into Fe with temperature increased, and the gap reduced gradually.

Mechanical and Microstructural Properties Investigation on Rheocast Automotive Parts Using A356 Alloy

2006 ◽  
Vol 116-117 ◽  
pp. 489-492 ◽  
Author(s):  
Chang Ik Ma ◽  
Ho Do Lee ◽  
Dae Up Kim
Keyword(s):  
Mechanical Properties ◽  
A356 Alloy ◽  
Mold Temperature ◽  
Solidification Structure ◽  
Slow Cooling ◽  
Automotive Parts ◽  
Semi Solid ◽  
Mechanical And Microstructural Properties ◽  
Forced Cooling ◽  
Better Than

Variations of cooling characteristics and solidification microstructure were investigated at various melt pouring temperature, mold temperature and cooling condition for semi-solid slurry of A356 alloy. And metallurgical and mechanical properties were examined with testing samples made by rheocast process based on the obtained cooling conditions. Undercooled state of melt appeared when superheating of melt was below 35, and it was easy to form equiaxed solidification structure. Forced cooling hardly ever contributed to globular shaping of microstructure although it helped a little to refine microstructure. And slow cooling through insulation and mold heating was effective to form globular shape. Also, the metallurgical and mechanical properties of samples made by this process were better than those of other sample made by conventional processes.

Study on the Microstructure and Mechanical Properties of 15CrMoR

2012 ◽  
Vol 472-475 ◽  
pp. 2731-2735
Author(s):  
Xiao Dong Hu ◽  
Qing Kun He ◽  
Jian Tao Lv ◽  
Yong Zhang
Keyword(s):  
Mechanical Properties ◽  
Arc Welding ◽  
Weld Zone ◽  
Submerged Arc Welding ◽  
Butt Weld ◽  
Heat Treated ◽  
Electric Arc Welding ◽  
The Relationship ◽  
Submerged Arc ◽  
Better Than

The butt weld sample with the material of 15CrMoR has been manufactured with the bonding methods of manual electric arc welding (SMAW) and submerged-arc welding (SAW). The relationship between the microstructure and the mechanical properties has been analyzed in this paper, and the conclusions have been obtained as followed: only the last weld layer has the obvious zones of weld zone, heat-affected zone (HAZ) and fusion area for the multi-layer butt weld, the weld zone and the fusion area will be heat-treated by the next layer welding; the hardness along central intersection shows a W-shaped distribution, and the zone with normalizing organization has the lowest hardness and the surface layer has the highest hardness; the mechanical properties of the multi-layer butt weld are much better than the monolayer weld’s.

Anodizing of A356 T6 Alloys Obtained by Sub-Liquidus Casting

2008 ◽  
Vol 141-143 ◽  
pp. 755-760 ◽  
Author(s):  
Antonio Forn ◽  
Isabel Espinosa ◽  
Maite T. Baile ◽  
Elisa Rupérez
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Oxide Layer ◽  
Silicon Crystals ◽  
Wear And Corrosion ◽  
Coating Formation ◽  
Trapped Gas ◽  
Semi Solid ◽  
Wear And Corrosion Resistance ◽  
Coating Growth

Semi solid processing reduces porosity and amount of trapped gas and it allows heat treatment T6 that improves a hard anodized oxide layer. The aim of this work is to show the anodizing possibility of A356 T6 components conformed by Sub-liquidus Casting (SLC) to improve wear and corrosion resistance. This work compares the anodizing effect on tribological properties and corrosion resistance between components obtained by A6061 T6 extruded alloys and from A356 T6 produced by SLC. The effect of rounded silicon crystals on the coating formation and the fracture produced during the coating growth are described.

scholarly journals CrMnFeCoNi high entropy alloys with carbon and nitrogen: mechanical properties, wear and corrosion resistance

2021 ◽  
Vol 3 (11) ◽  
Author(s):  
L. Chmielak ◽  
L. Mujica Roncery ◽  
P. Niederhofer ◽  
S. Weber ◽  
W. Theisen
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Austenitic Steels ◽  
High Entropy Alloys ◽  
Interstitial Free ◽  
High Entropy ◽  
Carbon And Nitrogen ◽  
Wear And Corrosion ◽  
Wear And Corrosion Resistance ◽  
The Impact

AbstractThe use of interstitial elements has been a key factor for the development of different kinds of steels. However, this aspect has been little explored in the field of high entropy alloys (HEAs). In this investigation, the effect of carbon and nitrogen in a near-equiatomic CrMnFeCoNi HEA is studied, analyzing their impact on the microstructure, and mechanical properties from 77K to 673K, as well as wear, and corrosion resistance. Carbon and nitrogen are part of the FCC solid solution and contribute to the formation of precipitates. An increase in the yield and ultimate tensile strength accompanied with a decrease in the ductility are the main effects of C and N. The impact toughness of the interstitial-free material is higher than that of C and C+N alloyed systems. Compared to CrNi and CrMn austenitic steels, the wear resistance of the alloys at room temperature is rather low. The surface corrosion resistance of HEAs is comparable to austenitic steels; nevertheless HEAs are more susceptible to pitting in chloride containing solutions.

Microstructure and Mechanical Properties of Semi-Solid Die-Cast A356 Aluminum Alloy

2016 ◽  
Vol 877 ◽  
pp. 39-44
Author(s):  
Si Min Lei ◽  
Li Gao ◽  
Yohei Harada ◽  
Shinji Kumai
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
A356 Aluminum Alloy ◽  
Microstructure And Mechanical Properties ◽  
Die Cast ◽  
Microstructural Evaluation ◽  
Cast Machine ◽  
A356 Aluminum ◽  
Semi Solid ◽  
The Relationship

The present work deals with the relationship between microstructure and mechanical properties of A356 aluminum alloy which was produced via thixocasting process under different casting conditions. Feedstock billets were heated to a target temperature to obtain a semi-solid slurry with the required solid fraction. Some billets were heated to a fully-melted condition. In order to obtain fine and spheroidized Al grains, some billets for the partially melting were compressed axially by 33% at a room temperature before heating. The completely-melted and partially-melted slurries were die-cast by using a die-cast machine, and hour glass-shaped rod-type tensile specimens and small-size plate-type tensile specimens were obtained. Small cubic specimens were also collected from the die-cast products for microstructural evaluation. They were polished, and etched by Weck’s reagent. The partially-melted specimen which was compressed before heating shows the spherical Al grains. But the grain of the strain-free partially-melted specimen exhibited complicated morphology. The fully-melted specimen shows the fine and dendrite structure.

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