Investigation on the Microstructure Hardness for the Hot Compressed Duplex Steel

2022 ◽  
Vol 905 ◽  
pp. 30-37
Author(s):  
Shu Lan Zhang ◽  
Xiao Dan Zhang ◽  
Hai Feng Xu ◽  
Chang Wang
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Optical Microscope ◽  
Ferrite Phase ◽  
Ferrite Formation ◽  
Average Hardness ◽  
Duplex Steel ◽  
Quench Temperature ◽  
Fluctuation Range ◽  
Scanning Electron

Effect of microstructure size and type on the hardness for the duplex steel were disclosed by using of optical microscope (OM), scanning electron microscope (SEM) and nanoindenter for the samples hot compressed under different temperature with reduction of 10%, 30%, 50% and 70%. OM and SEM were used to measure the average martensite lamellar width, space and indenter morphology. nanoindenter test characterized the microstructure hardness for the samples under different process. Experiment results show that martensite hardness for the sample hot compressed at 950°C has larger diversity than that of sample hot compressed at 1200°C. The martensite hardness fluctuation range for the sample compressed at 950°C is almost from about 7GPa to 12GPa, while, for the sample compressed at 1200°C, the fluctuation range is basically from about 9GPa to 12GPa. However, the average hardness for the samples hot compressed at 950°C is comparably smaller, which is related with lower quench temperature. The larger martensite hardness fluctuation is mainly related with induced ferrite formation and finer martensite lamellar width. For the ferrite phase, the hardness fluctuation range is lower.

Effect of Casting Overheat and Rolling Temperature on Morphology of Sulfide in 30MnVS Steel

2012 ◽  
Vol 457-458 ◽  
pp. 270-273
Author(s):  
Yi You Tu ◽  
Guo Zhong Li
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Continuous Casting ◽  
Optical Microscope ◽  
Rolling Temperature ◽  
Ferrite Content ◽  
Continuous Casting Slab ◽  
Intragranular Ferrite ◽  
Sulfide Segregation ◽  
Scanning Electron

Effect of superheat and initial rolling temperature on the morphology and distribution of sulfide in non quenched and tempered free cutting steel 30MnVS has been studied by optical microscope and scanning electron microscope. Results show that proper superheat and initial rolling temperature can turn rod-shaped sulfide into massive or globular sulfide，to alleviate sulfide segregation and pro-eutectoid ferrite distribution along the boundary of pearlite clusters in 30MnVS , increase the intragranular ferrite content and optimize the structure of continuous casting slab.

Analysis of an Axle Failure under Torsional Load

2016 ◽  
Vol 850 ◽  
pp. 101-106 ◽  
Author(s):  
Shu Mei Li ◽  
Jian Jun Yang ◽  
Wei Dong Zhang ◽  
August Chang ◽  
Cai Xia Zhang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Failure Mechanism ◽  
Field Testing ◽  
Optical Microscope ◽  
Fatigue Lifetime ◽  
Torsional Load ◽  
Torsional Fatigue ◽  
Secondary Cracks ◽  
Scanning Electron

Premature fracture of an axle under torsional load occurred after a tracked military tank had experienced field testing for only 80 kilometers. Visual metallographic examinations were performed with optical microscope (OM) and scanning electron microscope (SEM). The investigation demonstrates that the premature fracture is caused by metallurgical problems inside the axle where the primary and secondary cracks originate, propagate, and eventually result in final catastrophic rupture through torsional fatigue. The failure mechanism is summarized and improvement of the fatigue lifetime for the axle is recommended.

CHARACTERISATION OF BIOMEDICAL TITANIUM LAYERS DEPOSITED BY A VACUUM PLASMA SPRAY PROCESS

2021 ◽  
Vol 55 (2) ◽  
pp. 231-235
Author(s):  
Mihailo Mrdak ◽  
Darko Bajić ◽  
Darko Veljić ◽  
Marko Rakin
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Hardness Test ◽  
Optical Microscope ◽  
Mechanical Tests ◽  
Test Method ◽  
Bonding Layer ◽  
Vacuum Plasma Spray ◽  
Porous Ti ◽  
Scanning Electron

In this paper we will describe the process of the deposition of thick layers of VPS-Ti coating, which is used as a bonding layer for the upper porous Ti coatings on implant substrates. In order to deposit the powder, we used HÖGANÄS Ti powder labelled as AMPERIT 154.086 -63 µm. In order to test the mechanical properties and microstructure of the VPS-Ti coating, the powder was deposited on Č.4171 (X15Cr13 EN10027) steel substrates. Mechanical tests of the microhardness of the coating were performed by the Vickers hardness test method (HV0.3) and tensile strength by measuring the force per unit area (MPa). The microhardness of the coating is 159 HV0.3, which is consistent with the microstructure. The coating was found to have a good bond strength of 68 MPa. The morphology of the powder particles was examined on a scanning electron microscope. The microstructure of the coating, both when deposited and etched, was examined with an optical microscope and a scanning electron microscope. By etching the coating layers, it was found that the structure is homogeneous and that it consists of a mixture of low-temperature and high-temperature titanium phases (α-Ti + β-Ti). Our tests have shown that the deposited layers of Ti coating can be used as a bonding layer for porous Ti coatings in the production of implants.

Clouding of Pressed Potassium Bromide Powder

1972 ◽  
Vol 26 (2) ◽  
pp. 247-251 ◽  
Author(s):  
William P. Norris ◽  
Allen L. Olsen ◽  
Richard G. Brophy
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Adsorbed Water ◽  
Optical Microscope ◽  
Potassium Bromide ◽  
Monomolecular Layer ◽  
Cloudy Region ◽  
Weak Zones ◽  
Ground Powder ◽  
Scanning Electron

The monomolecular layer of water adsorbed on KBr particles is responsible for clouding of disks pressed from finely ground powder. Cloudiness is caused by formation of a multitude of cracks in the disk. The initial cracking can be observed with a low power optical microscope and the extensive cracking in the fully cloudy region is observable with a scanning electron microscope. It is suggested that adsorbed water promotes recrystallization, generating weak zones in the workhardened, elastically stressed disk which fails by cracking.

Influence of prophylaxis on the microleakage of sealants: in vitro study

2002 ◽  
Vol 26 (4) ◽  
pp. 371-375 ◽  
Author(s):  
Ana Beatriz Alonso Chevitarese ◽  
Orlando Chevitarese ◽  
Ivete Pomarico Ribeiro de Souza ◽  
Roberto Braga de Carvalho Vianna
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
In Vitro Study ◽  
Optical Microscope ◽  
Vitro Study ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
Scanning Electron

The aim of this study was to evaluate the influence of prophylaxis on the sealants microleakage in 30 premolars divided into: Group A, Group B and Group C. The teeth were analyzed using the optical microscope (OM) and at scanning electron microscope (SEM). There was a statitical significant difference among the groups regarding the presence of microleakage, but not with the presence of tags.

scholarly journals Susceptibility of Populus x euramericana ‘I-214’ of Spanish origin to xylophagous attacks: durability tests for its possible inclusion in European standard

2019 ◽  
Vol 28 (2) ◽  
pp. e008
Author(s):  
Eleana Spavento ◽  
Mónica Murace ◽  
Luis Acuña ◽  
Silvia Estela Monteoliva ◽  
Mª Teresa Troya
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Parenchyma Cell ◽  
Soft Rot ◽  
Dry Mass ◽  
Optical Microscope ◽  
Test Material ◽  
Fungal Colonization ◽  
Populus X Euramericana ◽  
Scanning Electron

Aim of study: to assess the natural durability of Populus x euramericana ‘I-214’ against xylophagous fungi and termites, and to carry out a macro-microscopic analysis of the alterations caused by each xylophagous agent in order to get the necessary information for its possible inclusion in existing European standards.Area of study: A 20-years-old commercial plantation Populus x euramericana‘I-214’ located in Quintanilla de Sollamas (42° 36′ 00″N - 05° 49′ 00″ W), Spanish community of Castile-LeonMaterial and methods: material sampling and selection was carried out following EN 350:2017 for commercial sawn timber. Poplar resistance to xylophagous basidiomycete, soft rot fungi and subterranean termites was determined according to CEN/TS 15083-1:2005, CEN/TS 15083-2:2005 and EN 117:2012, respectively. The durability and use classes were estimated according to EN 350:2016 and EN 335:2013, respectively. The anatomical studies were carried out with Optical and Scanning Electron Microscope. Material characterization was carried out by reference to Anagnost (1998) and Schwarze (2007).Main results: ‘I-214’ poplar wood proved to be “Not-durable” to the action of basidiomycetes, soft rot fungi and termites, use classes 1-2, and showed macro-microscopic evidence of these types of decay.Research highlights: the information obtained in this study would allow the inclusion of clone I-214 in the standard EN 350 and its explicit classification within it.Keywords: wood-decay fungi; termites; EN 350.Abbreviations used: TM: test material; RM: reference material; RH: relative humidity; ML: mass loss; mi: initial dry mass; mf: final dry mass; DC: durability class; OM: Optical Microscope; SEM: Scanning Electron Microscope; TS: transverse section samples; LS: longitudinal section samples; CI: robust confidence intervals; F: fibre; V: vessel; h: hole; t: erosion trough; R: radial parenchyma cell; ep: erosion pitting; Fc: fungal colonization; fr: fracture; c: cavity; b: bore hole; m: mycelium.

scholarly journals Toward Operations in a Surgical Scenario: Characterization of a Microgripper via Light Microscopy Approach

2019 ◽  
Vol 9 (9) ◽  
pp. 1901 ◽  
Author(s):  
Federica Vurchio ◽  
Pietro Ursi ◽  
Francesco Orsini ◽  
Andrea Scorza ◽  
Rocco Crescenzi ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Statistical Analysis ◽  
Scanning Electron Microscope ◽  
Light Microscopy ◽  
Mechanical Systems ◽  
Optical Microscope ◽  
Micro Electro Mechanical Systems ◽  
Mems Technology ◽  
Scanning Electron

Micro Electro Mechanical Systems (MEMS)-Technology based micro mechanisms usually operate within a protected or encapsulated space and, before that, they are fabricated and analyzed within one Scanning Electron Microscope (SEM) vacuum specimen chamber. However, a surgical scenario is much more aggressive and requires several higher abilities in the microsystem, such as the capability of operating within a liquid or wet environment, accuracy, reliability and sophisticated packaging. Unfortunately, testing and characterizing MEMS experimentally without fundamental support of a SEM is rather challenging. This paper shows that in spite of large difficulties due to well-known physical limits, the optical microscope is still able to play an important role in MEMS characterization at room conditions. This outcome is supported by the statistical analysis of two series of measurements, obtained by a light trinocular microscope and a profilometer, respectively.

A Novel Approach on Fractography Through Infrared Microscopy

2019 ◽  
Author(s):  
Allan Norico ◽  
Rommel Estores
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Mechanical Stress ◽  
Optical Microscope ◽  
Secondary Crack ◽  
Infrared Microscopy ◽  
Novel Approach ◽  
Electrical Overstress ◽  
Scanning Electron

Abstract Some of the most challenging task in analyzing fractures is a die that has not been fully cracked apart and a cracked die with electrical overstress damage. Traditional tools such as simple magnifying lens, optical microscope and up to the advance Scanning Electron Microscope are not enough to study the internal fractures or markings that could lead back to the origin of the crack. In order to study these internal fractures, the analyst tends to break the sample into pieces. However, this method creates additional mechanical stress and leads to a secondary crack where the point of origin will be difficult to analyze. This paper aims to introduce infrared microscopy in fractography (mainly on silicon) using cases and techniques to minimize the occurrence of secondary crack in analyzing internal fractures.

Fabrication of Microchannels on SiC Substrate by Femtosecond Laser

2012 ◽  
Vol 557-559 ◽  
pp. 1322-1325 ◽  
Author(s):  
Yi He Li ◽  
Hua Xiao ◽  
Gong Yi Li ◽  
Jian Feng ◽  
Xiao Dong Li
Keyword(s):  
Silicon Carbide ◽  
Electron Microscope ◽  
Laser Pulse ◽  
Scanning Electron Microscope ◽  
Femtosecond Laser ◽  
Optical Microscope ◽  
Pdms Stamp ◽  
The Relationship ◽  
Scanning Electron ◽  
Micro Patterns

A novel femtosecond laser directly writing method was utilized to fabricate microchannels on silicon carbide (SiC) substrate. The micro patterns were transferred to a Polydimethylsiloxane (PDMS) stamp, characterized by both optical microscope and scanning electron microscope (SEM). The relationship between size (depth and width) of channels and power of laser pulse were discussed in detail.

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