Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userEffect of sintering time on the apparent density and the final dimensions of the produced compact by technique metal powders
تأثير زمن التلبيد الحراري على الكثافة الظاهرية و الأبعاد النهائية للمدمج المنتج بتقانة المساحيق المعدنية
1487
0 151
4.0
(
1
)
Created by
Shamra Editor
Ask ChatGPT about the research
دُرِسَ في هذا البحث مجموعة من التجارب لعملية تدميج (Compacting) عدة مساحيق معدنية (Powder Metal) تشكل خليطة معدنية من مادة المساحيق ذات الأساس الحديدي لشكل هندسي أسطواني، و تم القيام بعدة اختبارات من أجل الوصول إلى العلاقة التي تربط الكثافة الظاهرية النهائية للمدمج مع زمن التلبيد الحراري، و دراسة مدى تغير الأبعاد الهندسية للمدمج النهائي بعد الانتهاء من عملية التلبيد الحراري خلال فترات زمنية مختلفة. بينت نتائج الاختبارات و القياسات أن زمن التلبيد الحراري يؤثر بشكلٍ إيجابي على الكثافة الظاهرية للمدمج النهائي المصنع بتقانة المساحيق المعدنية، و بالتالي ستزداد متانته، حيث التناسب يكون طردياً حتى الوصول إلى حد معين. و أيضاً تأثيره كان واضحاً على تقلص أقطار العينات المستخدمة في الاختبارات. و تغير (زيادة و نقصان) في ارتفاع العينات. أظهرت نتائج البحث الأهمية الكبيرة لمتابعة دراسة و تحليل العلاقات التي تربط متغيرات تقانة تدميج المساحيق المعدنية مع بعضها البعض، و تأثيراتها المختلفة على المدمج النهائي الناتج.
In this search, has been studied set of practical experiences for compacting several metal powders composed a metallic alloy based iron from powders with a proposed geometric shapes (cylindrical). Several tests were done in order to reach the relationship between the final apparent density for the compact with a sintering time, and study changing the geometric dimensions of the final compact after the completion of sintering process during different time periods. The tests and Measurement results had been demonstrated that sintering time affect positively on the apparent density of the final compact which Manufactured by technique metal powders, and thus will increase its strength, where proportionality is directly proportional access even to a certain extent. And also its effect was an obvious shrinking diameters samples used in the tests. And changing (increase or decrease) in height samples. Search has shown the great importance of the follow-up studying and analyzing the relationships which associate that variables of metal powders technique each other, and their different effect on the final compact.
References used
Powder metal technologies and applications, vol.7 of , ASM metals Handbook, USA 1998, p2762
SRIDHAR,I.A ;FLEC,N.A. Yield Behaviour of Cold Compacted Composite Powders, Acta Metallurgica Inc, vol 48 (2000) 3341-3352
ORBA,R.L.: New Research Directions in powder metallurgy, Reports in physics, Romanian, 2004 Volume 56, NO.3, P.505 – 516
rate research
Read More
In this research, It has been studied the effect of compaction pressure on
the final roughness for the top and down surfaces for the green compacts
that manufactured by meal powder technique and it has been studied also
the effect of piston veloci
ty (compaction velocity) on the final roughness
for the same two surfaces.
The results present that the curved for the top surface roughness is
completely decreasing and as the pressure has increased, the value for
roughness has reduced and the mean roughness (Ra) has very close
values, where these values have made curve from second degree and
opposite relationship. The results were same for the down surfaces but
with different variations.
Many constructionl systems were used in the construction of
airports. These systems vary according to the development of the
various aircraft models as well as to the increasing number of
passengers. This study will include a review of some airpor
ts
buildings, which had been built depending on the metal
construction technique that achieved larger architectural
dimensions and spaces for passenger terminal in terms of shape and
function.
This research includes a study of the evolution of the metal
technique used in airport construction especially for passenger
terminal showing its effect in realizing the architectural space
including its dimensions and spaces and in meeting the functional
requirements inside it particularly securing passengers safety,
comfort, and the ease of controlling their movement to the taking
off places, as well as securing ventilation and natural lighting of the
building.
Introduction:
While literature demonstrates that the optimum accuracy for final
impressions is obtained with the custom trays, the use of stock trays for silicone impressions appears to be popular if the proper impression technique was used.
Purpo
se:
This in vitro study was done to evaluate the linear dimensional stability of impression made in stock trays and custom trays with different techniques, using poly vinyl siloxane as an impression material.
Materials and methods:
Three different impression techniques was done as follows:
1- Putty wash 1- step technique using stock tray
2- Putty wash 2- step technique using stock tray
3- 1-step technique using custom tray
For each technique, fifteen impressions of a maxillary partial edenulous metal master model were made and then poured. The accuracy was assessed by measuring five dimensions on stone casts poured from impressions of the master model, then these measurments was compared with the measurments of the linear dimensions of the master model.
Results:
Although the first technique was the most accurate, the statistical analysis showed statistically insignificant difference among the three different impression techniques for the stability of the linear dimensions.
Conclusion :
Making custom tray is time consuming and costly; therefore putty wash 1-step technique in adapted stock trays can be used as an alternative to provide accurate impressions, as obtained from custom trays .
This research is done in an experiment by plaster in the
circumstances of Homs. The aim of this paper to study the effect of
adding four different levels of phosphogypsum as much as (0.00,
6.72, 13.44, 20.16)ton / hectare (three replicates for eac
h treatment)
on bulk density and structure stability for clay soil has taken from
(Kattina).
The results showed improvement in the stability of the structure of
soil specially (0.25-1)mm, increasing in aggregation degree ,
increasing of the rate of total porosity ,air filled porosity in
comparison to the control at the two levels(13.44, 20.16)ton/hectare
and also by increasing the added level . Whereas the dispersion
ratio , and Bulk density were decreased when increasing the level
of phosphogypsum at the same two levels.
The main achieved results in this study showed , a significant
increase in aggregation degree in the soil when increasing the ratio
of the added phosphogypsum at the levels( 6.72, 13.44, 20.16) in
comparasion with control .
In other way the dispersion ratio was decreased and had negative
relationship when increasing the level of the added
phosphogypsum in comparasion with control .
Among the factors affecting the movement of water in the soil are soil properties (structure and texture).
The rate of components of soil minerals and organic material has an effect on its bulk density. As the
surface soil has organic matter more t
han subsurface soil in general, the bulk density increases with soil
depth, so the research aims to study the effect of changing soil bulk density with depth on wetting front
advance under a trickle line source. The experimental work included a nine laboratory tests for
monitoring the advancement of the wetting front with time, The water advance and water distribution
measurement are carried out for three cases of the soil profile with the change of bulk density along soil
depth (0.00923,0.00462,0) gm/cm 3/cm: first case with the soil changed bulk density from 1.2 gm/cm 3 at
the soil surface and gradually to 1.8 gm/cm 3 at a maximum depth of the profile, the second case with the
soil changing bulk density from 1.5 gm / cm 3 to 1.8 gm / cm 3, and the third case homogeneous soil with
bulk density 1.2 gm / cm 3, and using three application flow rates 1.3,2.6,3.9 cm 3 / min / cm.
The study showed that with the increase in the change of bulk density along soil depth there is a small
increase in horizontal advance and almost non-existent increase in vertical advance while they are clear
and tangible in diagonal advance. It also showed that the amount of the increase in the vertical advance is
greater than in the horizontal advance and be could be in diagonal advance when increasing the
application flow rate, and all of the horizontal advance, vertical advance and the diagonal advance of the
wetting front increase with the decrease of the application flow rate when applied in the same volume of
water.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
