Influence of Pectin Fine Structure on the Mechanical Properties of Calcium−Pectin and Acid−Pectin Gels

2007 ◽  
Vol 8 (9) ◽  
pp. 2668-2674 ◽  
Author(s):  
Anna Ström ◽  
Pascual Ribelles ◽  
Leif Lundin ◽  
Ian Norton ◽  
Edwin R. Morris ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fine Structure ◽  
Pectin Gels

Microstructure and Properties of a Non-Quenched Prehardened Steel at Different Cooling Rate

2012 ◽  
Vol 524-527 ◽  
pp. 1976-1979
Author(s):  
Yi Luo ◽  
Jin Ming Peng
Keyword(s):  
Mechanical Properties ◽  
Fine Structure ◽  
Optical Microscopy ◽  
Cooling Rate ◽  
Retained Austenite ◽  
Transformation Products ◽  
Electronic Microscopy ◽  
Transmission Electronic Microscopy ◽  
Microstructure And Properties ◽  
Cooling Conditions

Mechanical properties of non-quenched prehardened (NQP) steel air cooled and sand cooled after forged were tested and their microstructure was investigated by optical microscopy and transmission electronic microscopy(TEM). The results show that mechanical properties of the NQP steel are similar at both cooling conditions, and their microstructure is bainite, whose fine structure is main bainite ferrite laths, retained austenite films, retained austenite islands and their transformation products. Bainite ferrite laths of the NQP steel air cooled are narrower than that sand cooled, while more retained austenite islands exist in latter.

scholarly journals Novel Approach of Nanostructured Bainitic Steels’ Production with Improved Toughness and Strength

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1220
Author(s):  
Peter Kirbiš ◽  
Ivan Anžel ◽  
Rebeka Rudolf ◽  
Mihael Brunčko
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fine Structure ◽  
Retained Austenite ◽  
Bainitic Ferrite ◽  
High Hardness ◽  
Tensile Tests ◽  
Isothermal Transformation ◽  
Impact Testing ◽  
Bainitic Steels

The tendencies of development within the field of engineering materials show a persistent trend towards the increase of strength and toughness. This pressure is particularly pronounced in the field of steels, since they compete with light alloys and composite materials in many applications. The improvement of steels’ mechanical properties is sought to be achieved with the formation of exceptionally fine microstructures ranging well into the nanoscale, which enable a substantial increase in strength without being detrimental to toughness. The preferred route by which such a structure can be produced is not by applying the external plastic deformation, but by controlling the phase transformation from austenite into ferrite at low temperatures. The formation of bainite in steels at temperatures lower than about 200 °C enables the obtainment of the bulk nanostructured materials purely by heat treatment. This offers the advantages of high productivity, as well as few constraints in regard to the shape and size of the workpiece when compared with other methods for the production of nanostructured metals. The development of novel bainitic steels was based on high Si or high Al alloys. These groups of steels distinguish a very fine microstructure, comprised predominantly of bainitic ferrite plates, and a small fraction of retained austenite, as well as carbides. The very fine structure, within which the thickness of individual bainitic ferrite plates can be as thin as 5 nm, is obtained purely by quenching and natural ageing, without the use of isothermal transformation, which is characteristic for most bainitic steels. By virtue of their fine structure and low retained austenite content, this group of steels can develop a very high hardness of up to 65 HRC, while retaining a considerable level of impact toughness. The mechanical properties were evaluated by hardness measurements, impact testing of notched and unnotched specimens, as well as compression and tensile tests. Additionally, the steels’ microstructures were characterised using light microscopy, field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM). The obtained results confirmed that the strong refinement of the microstructural elements in the steels results in a combination of extremely high strength and very good toughness.

scholarly journals Mechanical Properties and Fine Structure of Polypropylene Films

1965 ◽  
Vol 22 (244) ◽  
pp. 488-497
Author(s):  
Hyong-Dong Chu ◽  
Ryozo Kitamaru ◽  
Waichiro Tsuji
Keyword(s):  
Mechanical Properties ◽  
Fine Structure ◽  
Polypropylene Films

scholarly journals The thermoelastic properties of muscle and their molecular interpretation

1937 ◽  
Vol 124 (834) ◽  
pp. 29-56 ◽  
Keyword(s):  
Molecular Structure ◽  
Mechanical Properties ◽  
Fine Structure ◽  
Physical Properties ◽  
Mechanical Behaviour ◽  
Thermoelastic Properties ◽  
Molecular Interpretation

As is the case with all physical properties, the mechanical properties of an object may be referred ultimately to the arrangement of its atoms and the forces between them. It is therefore possible under certain con­ditions to draw conclusions about the fine structure of an object from its mechanical behaviour. The analysis of thermoelastic properties in particular has led, in a number of cases, to definite conclusions about molecular structure, and it has been the object of the work described here to apply the same method to the study of muscle.

scholarly journals Study of the thermal treatment modes influence on the forming of microstructure and specified complex of mechanical properties of high-strength sheet product with guaranteed level of hardness (400–450 HB) of low-alloyed steel

2019 ◽  
Vol 75 (4) ◽  
pp. 480-487
Author(s):  
M. Yu. Matrosov ◽  
P. G. Martynov ◽  
A. V. Mitrofanov ◽  
K. Yu. Barabash ◽  
T. V. Goroshko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fine Structure ◽  
Thermal Treatment ◽  
Hot Rolling ◽  
High Strength ◽  
Controlled Rolling ◽  
Alloyed Steel ◽  
Accelerated Cooling ◽  
Cold Forming ◽  
Low Alloyed Steel

High-strength sheet product of low-alloyed steel, used at manufacturing of heavy-loaded structures, must have, apart from wear resistance, high toughness, good weldability, ability to hot and cold forming, machinability and low cost. Combination of these properties based on forming fine grain austenite structure before the martensitic transformation at definite its thermal treatment modes. Results of study of microstructure, fine structure and mechanical properties of high-strength boron-containing low-alloyed steel after different technological methods of the rolled product manufacturing presented: high-temperature hot rolling and twostages controlled rolling with accelerated cooling followed by thermal treatment – quenching with tempering. Variants of optimal modes of thermal treatment determined, providing combination of high level of impact toughness under negative temperatures, hardness and strength properties of sheet product. The two considered in the article technological variants, comprising treatment of low-alloyed steel with boron (hot rolling and two-stages controlled rolling with accelerated cooling) followed by thermal treatment results in forming fine structure of tempered martensite, which provides high mechanical properties, meeting the made requirements. Depending on the heating temperature before quenching in the range 770–950 °С, the morphology of the actual steel grain is changing from elongated to equiaxed, which is connected with the metal recrystallization process during heating after plastic deformation. The study results obtained allow to optimize the thermal treatment processes of sheet product of low-alloyed boron containing steel for particular conditions of application.

Sign in / Sign up

Export Citation Format

Share Document