scholarly journals Evaluation of porosity of AlZn5Mg castings made by squeeze casting technology

2019 ◽  
pp. 12-19
Author(s):  
Kinga Boroń
Keyword(s):  
Squeeze Casting ◽  
Middle Part ◽  
Squeeze Pressure ◽  
Gravity Casting ◽  
Hydrostatic Weighing ◽  
Structural Tests ◽  
Alloy Castings ◽  
Weighing Method ◽  
The Impact ◽  
Hydrostatic Weighing Method

The paper shows the results of research aimed to assess the impact of high squeeze pressure on the porosity of AlZn5Mg alloy castings, including its distribution in slab-type castings with dimensions of 25 x 100 x 200 mm. The research was carried out on castings made by two methods: squeeze casting and gravity casting. The pressing was conducted at a pressure of 100 MPa at an initial mould temperature of 200°C. The research identified the middle and outer parts of the casting. Experimental research was preceded by numerical simulation of the casting solidification, then a porosity assessment was carried out using the hydrostatic weighing method, which was supplemented by structural observations. The results of the research showed a two-fold decrease in the porosity in the middle part of the casting which is most exposed to the occurrence of shrinkage voids formed in the final clotting phase. Structural tests revealed the occurrence of dispersed porosity in castings, mainly of shrinkage and / or shrinkage-gas origin. The impact of pressure of 100 MPa during solidification caused fragmentation of the primary structure of castings, which resulted in a higher grain density.

Error determination of hidden flows by hydrostatic weighing in parts obtained by casting

2020 ◽  
pp. 339-342
Author(s):  
M.S. Razumov ◽  
P.V. Glazkov ◽  
V.S. Kochergin ◽  
A.S. Byshkin
Keyword(s):  
Theoretical Calculations ◽  
Casting Defects ◽  
Casting Method ◽  
Error Determination ◽  
Hydrostatic Weighing ◽  
Weighing Method ◽  
Hydrostatic Weighing Method

The existing methods for detecting of casting defects and their disadvantages are considered. Hydrostatic weighing method is proposed for detecting of hidden fl aws by comparing the reference and calculated densities of the casting, method for calculating of the error is recommended. The adequacy of theoretical calculations is verifi ed experimentally

scholarly journals ПОЛІМЕР-ПОЛІМЕРНИЙ КОМПОЗИТ НА ОСНОВІ ВІДХОДІВ ЗШИТОГО ЕТИЛЕНВІНІЛАЦЕТАТУ

2019 ◽  
Vol 128 (6) ◽  
pp. 64-70
Author(s):  
Б. П. Савчук ◽  
Б. М. Савченко ◽  
Н. В. Сова ◽  
І. М. Костюк
Keyword(s):  
Mechanical Properties ◽  
Melting Point ◽  
Polymer Composite ◽  
Constant Pressure ◽  
Capillary Viscometer ◽  
Hydrostatic Weighing ◽  
Weighing Method ◽  
Hydrostatic Weighing Method

Development of technology for the processing of cross liked EVA waste, followed by the use of polymer / polymer composite PVC / EVA as a filler. Method. The determination of the MFI was carried out in accordance with ISO 1133: 1997 on a capillary viscometer of constant pressure at a temperature of (190 ± 0,5) ° С and a weight of 2,16 kg. The thermostability  and  melting  point  are  determined  using  the  RM-200C  Hapro  rheometer  plastograph.  The mechanical properties were determined on a bursting machine according to the ASTM D638. Hardness - using  a  hard-gauge  with  a  Shore-D  scale,  the  density  by  hydrostatic  weighing  method  on  the  analytical scales RADWAG AS-X2.

scholarly journals Acurácia de índices alternativos para avaliar o estado nutricional de homens e mulheres

2017 ◽  
Vol 19 (3) ◽  
pp. 290
Author(s):  
Guilherme Adroaldo Moraes Pereira ◽  
Silvana Corrêa Matheus ◽  
Diego Rodrigo Both ◽  
Mauri Schwanck Behenck
Keyword(s):  
Nutritional Status ◽  
Fat Mass ◽  
Good Accuracy ◽  
Reference Method ◽  
Study Group ◽  
Fat Mass Index ◽  
Good Evaluation ◽  
Hydrostatic Weighing ◽  
Weighing Method ◽  
Hydrostatic Weighing Method

A good evaluation of the nutritional status requires knowledge on body composition, casting doubts on the accuracy of some indexes. herefore, the aim of this study was to analyze the accuracy of the following nutritional status indexes: Body Mass Index (BMI), BMI elevated to 2.5 (BMI2.5), Fat Mass Index (FMI) and BMI adjusted for fat mass (BMIfat). Participated of this study 280 subjects (aged 17-48 years), from which the results of BMI, BMI2.5, FMI and BMIfat indexes were analyzed, having the Hydrostatic Weighing method as reference. FMI presented the highest concordance value, but classiied as discrete (k=0.21). he other indexes presented small concordance with results of the reference method (k<0.20). In conclusion, none of the indexes investigated has good accuracy in assessing the nutritional status of the study group, considering that, although they show results of correlation with the reference method, they do not reach the minimum agreement criterion.

scholarly journals Density of Single Crystals of Ice from a Temperate Glacier

1955 ◽  
Vol 2 (18) ◽  
pp. 553-559 ◽  
Author(s):  
T. R. Butkovich
Keyword(s):  
Single Crystals ◽  
Maximum Error ◽  
Ice Crystals ◽  
Hydrostatic Weighing ◽  
Weighing Method ◽  
Error Computation ◽  
Crystal Aggregate ◽  
Hydrostatic Weighing Method

AbstractDensity of single crystals of ice from the Mendenhall Glacier near Juneau, Alaska, a temperate glacier, was determined by the hydrostatic weighing method. It was found that the densities of single crystals are slightly but measurably variable from one crystal to another. The values range from a minimum of 0.91712 gm./cm.3 to a maximum of 0.91728 gm./cm.3, when corrected for −3.5° C., for the eight crystals measured. Any imperfections such as Tyndall figures (hexagonal prismatic voids) were immediately evident in the density determinations, and correction for these imperfections give a corrected density essentially the same as that of clear specimens. Two clear crystal aggregate specimens tested had a lower density than the pure single ice crystals. An error computation gives the value of the estimated maximum error of the density determinations as ±2.1×10−5 gm./cm.3.

TEMPERATURE EFFECT ON DENSITY AND VISCOSITY OF LIGHT, MEDIUM, AND HEAVY CRUDE OILS

2020 ◽  
Author(s):  
D Sagdeev ◽  
◽  
Ch. Isyanov ◽  
I Gabitov ◽  
V Khairutdinov ◽  
...  
Keyword(s):  
Crude Oil ◽  
Atmospheric Pressure ◽  
Oil Field ◽  
Viscosity Data ◽  
Rotational Viscometer ◽  
Correct Operation ◽  
Hydrostatic Weighing ◽  
Weighing Method ◽  
Light Medium ◽  
Measured Density

The density and dynamic viscosity of four light, medium, and heavy (extra-viscous) crude oil samples from Tatarstan Oil Field (Russian Federation) have been measured over the temperature range from (293 to 473) K (for density) and from (293 to 348) K (for viscosity) at atmospheric pressure (101 kPa). The density measurements were made using a new densimeter based on hydrostatic weighing method. The viscosity measurements of the same crude oil samples were made us-ing Brookfield rotational viscometer (DV-II+PRO, LVD-II+PRO). The combined expanded uncertainty of the density, viscosity, atmospheric pressure, and temperature measurements at 0.95 confidence level with a coverage factor of k = 2 is estimated to be 0.16 %, 1.0 %, 1.0 %, and 20 mK, respectively. For validation of the reliability and accuracy of the measured density data and correct operation of the new densimeter, all oil samples were measured using the pycnometric method. The present study showed that the densities measured using the new hydrostatic weighing densimeter (HWD) are agree with the values obtained with pycnometric method within (0.03 to 0.14) %. The measured density and viscosity data were used to develop widerange correlations as a function of temperature and API characteristics. The measured densities were represented using simple function of temperature (polynomial type) with API gravity dependent parameters with an accuracy of AAD within from (0.10 to 0.18) %. The measured viscosity data were also used to develop linear Arrhenius and VTF models. API gravity dependence of the Arrhenius parameters was studied.

Mechanical Behaviour of Al7075 Hybrid Composites Developed through Squeeze Casting

2021 ◽  
Vol 13 (3) ◽  
Author(s):  
V. Gopal ◽  
D. Marx Raghu Raja ◽  
Jaikumar Mayakrishnan ◽  
V. Hariram
Keyword(s):  
Mechanical Properties ◽  
Squeeze Casting ◽  
Hybrid Composites ◽  
Casting Process ◽  
Processing Technique ◽  
Squeeze Pressure ◽  
Valve Body ◽  
Automotive Engine ◽  
Al 7075 ◽  
Brake Rotors

The automotive and aerospace sector are behind the development of squeeze casting process, as the squeeze cast components exhibit improved mechanical properties. Squeeze casting is a hybrid metal processing technique that combines the advantage of both casting and forging in one operation. The aluminium alloy 7075 is a futuristic material that is widely used to produce automotive and aerospace components. Cylindrical component of AL 7075 was produced by varying the squeeze pressure at certain level. The specimen was made from the component as per ASTM standard and they were tested for mechanical properties such as tensile hardness and impact strength respectively. It was found that mechanical properties were enhanced with increase in squeeze pressure. The aluminium 7075 hybrid composites developed through squeeze casting is fabricated and experimented upon and found to have adequate potential for wide variety of application. In aerospace industries it can be used in gear components, blade sleeves, guide vanes, wing components etc. Applications in surface transport are brake rotors, automotive engine cylinder, engine exhaust valve, body chassis and connecting rods. This material can be used in light weight applications such as power lines and wind mill fans.

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