No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Hardness of the High Pressure Die Castings from Alloy AlSi9Cu3 in dependence on the Subsequent Processing Technology
Abstract
The paper deals with the hardness of pressure die castings in dependence on the method of their subsequent processing. As a crucial influence there was taken cooling rate of parts after their removal from the pressure die mould. Moreover there was monitored influence of the machining allowance and the thermal treatment. Measurement of hardness was done on die castings from alloy AlSi9Cu3(Fe) by methods acc. to Brinell and acc. to Rockwell. Regarding reality that properties of die castings are influenced also by filling method, for the experiment there was chosen part casted by so-called central ingate where exists presumption for the uniform filling and thus also uniform distribution of casting properties. The measurement took place for 2 months after casting, machining and eventually after thermal treatment of parts. On the basic of measured hardness values by methods acc. to Brinell and Rockwell there was determined the converting coefficient between these values.
... The hardness measurement was performed on turned samples by injection a ball with 2.5 mm diameter at a load 612.916N for 10 seconds. [15,16] ...
Treatment of metal alloys is one of the ways to affect the quality and properties of the material At the Faculty of Mechanical Engineering of the Jan Evangelista Purkyně University in Ústí nad Labem, one part of the research consists of searching for the influence of various modifying and inoculating elements on selected aluminium alloys. One of the alloys undergoing the present research is the hardening aluminium alloy AlSi9CuMnNi. The article describes one from these experiments, than AlSi9CuMnNi alloy was modified with various amounts of calcium (0.05, 0.1 and 0.15 wt. % Ca) and 0.2 wt. % Sb. The alloy without modification and with 0.2 wt. % Sb was heat-treated, too. In the experiment were made three castings for each type of alloy. Experimental samples were evaluated form view of final hardness, were machined, too and there were analysed tool wear of using cutting inserts and final ship from machining (turning). Presented experiments are part of the extensive research undertaken at FME at JEPU in Ústí nad Labem.
The aim of the research was to evaluate influence of porosity size on mechanical properties of AlSi7Mg0.3 (EN AC 42 100) alloy before and after thermal treatment. For the analyses casts of the same production type (forms used for tires production) were used. They were casted employing low-pressure casting technology. Since the negative influence of porosity on mechanical properties of Al alloys is generally known there is no quantitative assessment. In this research relation of porosity size in the structure of AlSi7Mg0.3 alloy and its mechanical properties is verified and quantified. Static tensile testing has proven the relation between porosity size in a structure of an Al material and its mechanical properties. Image analysis was applied in quantitative measurement of the porosity. The measurement was performed on prepared metallographic specimens. Porosity size is considered as a fraction of pore area to the total area of the analyzed specimen and is taken in percentage.
The aim of the work was carried out research on the causes cracking formed aluminum work pieces in the assortment of rods, which sometimes occur in the mechanical machining (turning, drilling) for alloys of Al-Cu. A typical representative for the machining of aluminum alloys is AlCu4MgMnPb alloy, most of which performs heat treatment for hardening increases the ultimate strength. For the given alloy were carried out qualitative and quantitative fractographic analysis of fracture surfaces after machining in order to determine possible causes cracking of the material and thus his insufficient strength. This paper clearly documented that the fractographic analysis methods can clearly and in the extent required to provide answers to the causes of insufficient strength of the material when cutting. At the same time points out the possible causes of cracks in this alloy in machining and ways for their elimination.
Al-Si Alloys are a leading casting alloys based on aluminum. Machining of aluminum alloys is currently frequently used and it is an important area of production. The paper deals with an experiment, that was realized at the Faculty of Production Technology and Management, University of Jan Evangelista Purkyne in Ústí nad Labem, where was machined alloy AlSi7Mg0.3. Samples were made for machining because of the master alloys of AlSi7Mg0.3, where part of the castings was left in its original condition and part of the castings was modified by strontium. This paper describes the evaluation of surface roughness obtained after machining of these castings in terms of how the modification by strontium can affect this.
Encyklopedie hliníku
- Š Michna
- I Lukáč
MICHNA, Š., LUKÁČ, I. a kol. (2005). Encyklopedie hliníku, pp. 253 -310, Adin s.r.o., Prešov SR.
Závislost tvrdosti odlitků Al slitin na době stárnutí a průběhu tepelného zpracování
- J Kopecký
KOPECKÝ, J. Závislost tvrdosti odlitků Al slitin na době stárnutí a průběhu tepelného zpracování. [online]. Praha:
ČVUT, FS Praha. Dostupné z: http://stc.fs.cvut.cz/pdf13/2616.pdf.
Vliv tepelného zpracování na mechanické vlastnosti a korozní odolnost hliníkových slitin
- ŠERÁK
ŠERÁK, J. a kol. (2015) Vliv tepelného zpracování na mechanické vlastnosti a korozní odolnost hliníkových
slitin. In Slévárenství, LXIII, Vol. 5 -6, 2015, pp. 158 -162.
Prínos metalografie při studiu zlievarenských Al zliatin skupiny 4xxxx
- L Hurtalová
- E Tillová
- M Chalupová
HURTALOVÁ, L., TILLOVÁ, E., CHALUPOVÁ, M. (2014). Prínos metalografie při studiu zlievarenských Al
zliatin skupiny 4xxxx. In Slévárenství, LXII, Vol. 11-12, 2014, pp. 417 -421.
Vliv modifikátorů na obrobitelnost a vlastnosti Al-Si slitin
- MARTINOVSKÝ
MARTINOVSKÝ, M., MÁDL, J. (2014). Vliv modifikátorů na obrobitelnost a vlastnosti Al-Si slitin. In Strojírenská technologie, XIX, Vol. 3 -4, 2014, pp. 212 -219.
Prínos metalografie při studiu zlievarenských Al zliatin skupiny 4xxxx
- HURTALOVÁ