Aluminium and aluminium alloys. Environmental aspects of aluminium products. General guidelines for their inclusion in standards

2015 ◽  
Keyword(s):  
Aluminium Alloys ◽  
Environmental Aspects

“Cavity” formation in superplastically deformed aluminium alloys

1990 ◽  
Vol 48 (4) ◽  
pp. 958-959
Author(s):  
A. Cziráki ◽  
E. Ková-csetényi ◽  
T. Torma ◽  
T. Turmezey
Keyword(s):  
Grain Boundaries ◽  
Aluminium Alloys ◽  
Superplastic Deformation ◽  
Volume Fraction ◽  
Superplastic Forming ◽  
Polished Surface ◽  
Cavity Formation ◽  
Stress Concentrations ◽  
Electron Microscopic ◽  
Commercial Aluminium

It is known that the formation of cavities during superplastic deformation can be correlated with the development of stress concentrations at irregularities along grain boundaries such as particles, ledges and triple points. In commercial aluminium alloys Al-Fe-Si particles or other coarse constituents may play an important role in cavity formation.Cavity formation during superplastic deformation was studied by optical metallography and transmission scanning electron microscopic investigations on Al-Mg-Si and Al-Mg-Mn alloys. The structure of particles was characterized by selected area diffraction and X-ray micro analysis. The volume fraction of “voids” was determined on mechanically polished surface.It was found by electron microscopy that strongly deformed regions are formed during superplastic forming at grain boundaries and around coarse particles.According to electron diffraction measurements these areas consist of small micro crystallized regions. See Fig.l.Comparing the volume fraction and morphology of cavities found by optical microscopy a good correlation was established between that of micro crystalline regions.

Factors Related to Childhood Suicides

Crisis ◽  
2014 ◽  
Vol 35 (5) ◽  
pp. 292-300 ◽  
Author(s):  
Rebecca Soole ◽  
Kairi Kõlves ◽  
Diego De Leo
Keyword(s):  
Child Death ◽  
Behavioral Difficulties ◽  
Childhood And Adolescence ◽  
Environmental Aspects ◽  
Indigenous Children ◽  
External Causes Of Death ◽  
External Causes ◽  
Causes Of Deaths ◽  
Gender Asymmetry ◽  
Control Study

Background: Suicide among children under the age of 15 years is a leading cause of death. Aims: The aim of the current study is to identify demographic, psychosocial, and psychiatric factors associated with child suicides. Method: Using external causes of deaths recorded in the Queensland Child Death Register, a case-control study design was applied. Cases were suicides of children (10–14 years) and adolescents (15–17 years); controls were other external causes of death in the same age band. Results: Between 2004 and 2012, 149 suicides were recorded: 34 of children aged 10–14 years and 115 of adolescents aged 15–17 years. The gender asymmetry was less evident in child suicides and suicides were significantly more prevalent in indigenous children. Children residing in remote areas were significantly more likely to die by suicide than other external causes compared with children in metropolitan areas. Types of precipitating events differed between children and adolescents, with children more likely to experience family problems. Disorders usually diagnosed during infancy, childhood, and adolescence (e.g., ADHD) were significantly more common among children compared with adolescents who died by suicide. Conclusion: Psychosocial and environmental aspects of children, in addition to mental health and behavioral difficulties, are important in the understanding of suicide in this age group and in the development of targeted suicide prevention.

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