Influence of the structure of blanked materials upon the blanking quality of copper alloys

One of the ways to improve the quality of steel production by rolling is the creation of additional streams of the metal flow, i.e. intensification of shear deformation not only in longitudinal but also in transverse direction. From the review of scientific-technical and patent literature it is known that to improve the quality of products when rolling usually use a system of alternating projections and depressions, which is created on the surface of the wide faces of slab or on work rolls. In this case, along with deformation in altitudinal and longitudinal directions, the conditions for deformation of the metal in the transverse direction, which has a positive effect on reducing the anisotropy of properties. Knowing the advantages of rolling with additional shear deformations, we have developed energy-saving technology of plate billets rolling of non-ferrous metals and alloys, allowing to obtain a uniform fine-grained structure throughout the volume of the workpiece, and designed two new constructions of the pair of work rolls with embossed surface as an annular groove, forming a trapezoidal protrusions and depressions alternating each other along the entire length of the barrel (the first pair to unequal treatment of the ledge to the depression and the second pair with equal respect to the ledge to the depression) to implement this technology in practice. In this paper were described results of investigations of microstructure evolution of copper alloys by rolling on the proposed technology in the relief rolls and according to the current technology in smooth rolls.

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3DP Technology for the Manufacture of Molds for Pressure Casting

Archives of Foundry Engineering ◽

10.1515/afe-2016-0058 ◽

2016 ◽

Vol 16 (3) ◽

pp. 99-102 ◽

Cited By ~ 1

Author(s):

G. Skorulski

Keyword(s):

Calcium Sulfate ◽

Copper Alloys ◽

Three Dimensional ◽

Pressure Casting ◽

Gravity Casting ◽

Three Dimensional Printing ◽

Comparative Feature ◽

Dimensional Printing ◽

Calcium Sulfate Hemihydrate

Abstract The paper presents the use of rapid prototyping technology of three dimensional printing (3DP) to make a prototype shell casting mold. In the first step, for identification purposes, a mold was prepared to enable different alloys to be cast. All molds being cast were designed in a universal CAD environment and printed with the zp151 composite material (Calcium sulfate hemihydrate) with a zb63 binder (2-pyrrolidone). It is designated to be used to prepare colourful models presenting prototypes or casting models and molds. The usefulness of 3DP technology for use with copper alloys, aluminum and zinc was analyzed. The strength of the mold during casting was assumed as a characteristic comparative feature in the material resistance to high temperature, the quality of the resulting casting and its surface roughness. Casting tests were carried out in vacuum – pressure casting. The casting programs applied, significantly increased the quality of castings and enabled precise mold submergence. Significant improvement was noted in the quality compared to the same castings obtained by gravity casting.

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New Copper Alloys Used to Make Products Intended for Contact with Drinking Water

Materials ◽

10.3390/ma14216301 ◽

2021 ◽

Vol 14 (21) ◽

pp. 6301

Author(s):

Michał Chruściński ◽

Szymon Szkudelski ◽

Jacek Borowski ◽

Artur Meller ◽

Marcin Suszyński

Keyword(s):

Structural Characteristics ◽

Copper Alloys ◽

Tensile Tests ◽

Primary Objective ◽

Production Plant ◽

Test Results ◽

Static Tensile ◽

Specific Temperature ◽

Degree Of Filling

This article presents the results of tests conducted as part of a research project with the primary objective of developing new copper alloys with limited lead content. The new group of materials were created in a production plant. As part of tests, a group of 22 alloys were selected for testing in castability, structural characteristics and hardness. Based on the test results obtained, the group of alloys under study was narrowed down to nine. The mechanical properties of these alloys were determined in static tensile tests as well as in uniaxial upsetting tests at elevated temperature, on the basis of which the group of alloys under investigation was further narrowed to three. Further studies involved technological verification of the application of these alloys under industrial conditions. These alloys were subject to numerical forging analyses, along with forging tests, under semi-industrial conditions, where the degree of filling of a die impression at a specific temperature was measured using an optic scanner. The quality of production of the obtained forgings was evaluated macroscopically with simultaneous observations of the microstructure.

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Stages of technological improvement of the process of continuous casting of iron-carbon and copper billets

History of science and technology ◽

10.32703/2415-7422-2020-10-2-217-249 ◽

2020 ◽

Vol 10 (2) ◽

pp. 217-249

Author(s):

Oleg Khoroshylov ◽

Valentyna Kuryliak ◽

Oleg Podoliak

Keyword(s):

Mechanical Properties ◽

Continuous Casting ◽

Copper Alloys ◽

Static Friction ◽

Fourth Stage ◽

Second Stage ◽

Technological Improvement ◽

Third Stage ◽

Unstable Process

In the article there are presented the stages of improvement of the process of continuous casting. It is revealed, that at the each stage of technological improvement of the process of continuous casting, the damage parameters of billets were reduced. Improvement of the process of continuous casting leads to the improvement of the mechanical properties of the billets and the performance of continuous casting machines. The first stage is shown as the process of transition of the number of experimental developments into quality, during which the casting of billets passed from an unstable process to a stable one. The second stage is characterized by the creation of new improved continuous casting processes. So, besides the existing machines of the vertical type, radial, curvilinear and horizontal casting machines were invented. By the end of the twentieth century, this technological process reached the limit of the possibilities for increasing the quality of performs, and the productivity of continuous casting machines. It is shown that the third stage is intended for continuous casting of copper alloys and is based on the influence of the frequency of the movement of the billets and the reverse movement of the perform during overcoming the static friction force. It was determined that for the frequency of movement of billets made of copper alloys, which are in the range of 2.5...7.5 min-1, the direction of its movement during overcoming the static friction affects the mechanical properties of the billet. The fourth stage - causes an increase in the mechanical properties of the billet due to the use of inertia forces in the alternating movement of the billet. It was revealed that at the fourth stage the mechanical properties of the billets increased most effectively, and the linear performance increased from 0.4...0.8 to 2.5...4.0 m/min, and in some cases to 5.0...7.0 m/min.

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Annotation: Class Size and the Quality of Educational Outcomes

Journal of Child Psychology and Psychiatry ◽

10.1017/s0021963098002819 ◽

1998 ◽

Vol 39 (6) ◽

pp. 797-804 ◽

Cited By ~ 8

Author(s):

Neville Bennett

Keyword(s):

Educational Outcomes ◽

Class Size

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Immunoferritin localization of intracellular antigens in positively stained frozen sections

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010008170x ◽

1978 ◽

Vol 36 (2) ◽

pp. 168-169

Author(s):

K. T. Tokuyasu

Keyword(s):

Surface Tension ◽

Water Surface ◽

Thin Layers ◽

The Other ◽

Positive Staining ◽

Frozen Sections ◽

The Past ◽

Ultrathin Frozen Sections ◽

Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

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Lithography below 100 nm

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100074367 ◽

1983 ◽

Vol 41 ◽

pp. 96-99

Author(s):

L. D. Jackel

Keyword(s):

Spatial Distribution ◽

Electron Beam ◽

Electron Scattering ◽

Electron Beam Lithography ◽

Substrate Material ◽

Local Electron ◽

Electron Dose ◽

Positive Resist ◽

Exposure Process

Most production electron beam lithography systems can pattern minimum features a few tenths of a micron across. Linewidth in these systems is usually limited by the quality of the exposing beam and by electron scattering in the resist and substrate. By using a smaller spot along with exposure techniques that minimize scattering and its effects, laboratory e-beam lithography systems can now make features hundredths of a micron wide on standard substrate material. This talk will outline sane of these high- resolution e-beam lithography techniques.We first consider parameters of the exposure process that limit resolution in organic resists. For concreteness suppose that we have a “positive” resist in which exposing electrons break bonds in the resist molecules thus increasing the exposed resist's solubility in a developer. Ihe attainable resolution is obviously limited by the overall width of the exposing beam, but the spatial distribution of the beam intensity, the beam “profile” , also contributes to the resolution. Depending on the local electron dose, more or less resist bonds are broken resulting in slower or faster dissolution in the developer.

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Convergent Beam Electron Diffraction

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070072 ◽

1978 ◽

Vol 36 (3) ◽

pp. 304-315

Author(s):

G. Lehmpfuhl

Keyword(s):

Electron Diffraction ◽

Diffraction Pattern ◽

Crystal Surface ◽

Diffraction Spot ◽

Crystal Thickness ◽

Large Area ◽

Electron Microscopic ◽

Additional Information ◽

Microscopic Investigations

Introduction In electron microscopic investigations of crystalline specimens the direct observation of the electron diffraction pattern gives additional information about the specimen. The quality of this information depends on the quality of the crystals or the crystal area contributing to the diffraction pattern. By selected area diffraction in a conventional electron microscope, specimen areas as small as 1 µ in diameter can be investigated. It is well known that crystal areas of that size which must be thin enough (in the order of 1000 Å) for electron microscopic investigations are normally somewhat distorted by bending, or they are not homogeneous. Furthermore, the crystal surface is not well defined over such a large area. These are facts which cause reduction of information in the diffraction pattern. The intensity of a diffraction spot, for example, depends on the crystal thickness. If the thickness is not uniform over the investigated area, one observes an averaged intensity, so that the intensity distribution in the diffraction pattern cannot be used for an analysis unless additional information is available.

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Observability of Very Thick Specimen by Using Transmission Scanning Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100064189 ◽

1971 ◽

Vol 29 ◽

pp. 26-27

Author(s):

K. Shibatomi ◽

T. Yamanoto ◽

H. Koike

Keyword(s):

Electron Microscope ◽

Image Quality ◽

Scanning Electron Microscope ◽

Chromatic Aberration ◽

Image Contrast ◽

Objective Lens ◽

Thick Specimen ◽

Transmission Electron ◽

Scanning Electron

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.

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