1. Instituto Universitario Politecnico “Santiago
Mariño”
Extension Porlamar
Macroestructura
Realizado Por:
Jose Castañeda
C.I. 23702402

2. Textual macrostructure
The text macrostructure is global semantic content representing meaning of a text. For a text is received as a
communication unit must possess a fundamental informative nucleus, which is the issue of dealing or theme.
The textual macrostructure, then, is a close to the subject or topic of the text, reinterpreted in the context of
discourse analysis concept.
If a sequence of sentences lacks overall macrostructure or theme, the whole is perceived as a series of
inconsistent statements, and, therefore, fails to establish itself as text. The macro-structure, in this sense, is a
mechanism of textual coherence. The subject does not have to be explicitly named in the text: if you are talking
about themed word or topic sentence, which has the important function of putting the reader in a position to
build the right macrostructure, as noted the likely subject of the rest of the speech , so it is no longer necessary
for the reader to build.
The concept of macro-structure is a relative concept: it refers both to the overall theme of the text as local issues
that develop in certain fragments. At the same time, like a Russian doll, the subthemes of certain textual
fragments may also have other related subtopics, which are therefore their own macrostructure. However,
strictly speaking, the macrostructure of the text will be more general and global, while certain parts of the text
may also have local paths macrostructures. As a result a hierarchical structure textual macrostructures obtained
on different levels. It depends on the extent and diversity of a text that addresses issues that present a semantic
structure more or less complex and hierarchical macrostructure. The text phrases are called macro-expressing
macropropositions sequences of sentences that summarize the global information of the text fragments and
themed entity; these macropropositions is reached by applying macrorules or cognitive operations that the reader
or listener to extract the macrostructure of a text.

3. Microestructura
 Welding using friction as the major resource
 No filler material involved
 Welds created by,
a) Frictional heating
b) Mechanical deformation

4. Friction Welding
 Heat from mechanical energy conversion
Linear friction welding
Rotary friction welding

5. Friction Stir Welding
Shoulder which creates friction
heat
and welding pressure
Probe which Stir the material
Sufficient downward force to maintain
pressure and to create friction heat
Rotating probe
provides friction
heat and pressure
which joins the
material Sufficient
downward force to
maintain
pressure and to
create friction heat

6. Microstructure Analysis
A. Unaffected material
B. Heat affected zone (HAZ)
C. Thermo-mechanically affected zone (TMAZ)
D. Weld nugget (Part of thermo-mechanically affected zone)

7. Microstructure analysis
Optical micrographs of regions (a), (b) and (c) of the stir nugget.

8. Advantages
 Diverse materials: Welds a wide range of alloys, including previously un-
weldable (and possibly composite materials)
 Durable joints: Provides twice the fatigue resistance of fusion welds.
 Versatile welds: Welds in all positions and creates straight or complex-
shape welds
 Retained material properties: Minimizes material distortion
 Safe operation: Does not create hazards such as welding fumes, radiation,
high voltage, liquid metals, or arcing
 No keyholes: Pin is retracted automatically at end of weld
 Tapered-thickness weld joints: Pin maintains full penetration

9. Comparison with other joining processes
FSW vs Fusion Welding FSW vsRivetting
» Improved Mechanical
Properties
» Reduced Distortion
» Reduced Defect Rate
» Parent Metal Chemistry
» Simplifies Dissimilar Alloy
Welding
» Fewer Process Variables
» Eliminates Consumables
» Reduces Health Hazard
» Reduced Part Count
» Reduced Production
Time
» Reduced Defect Rates
» Increase in Load
Carrying Capability»
Improved Fracture
Performance
» Eliminates Consumables
» Less Operator
Dependent

10. Comparison with other joining processes
FSW vs Fusion Welding FSW vsRivetting
» Improved Mechanical
Properties
» Reduced Distortion
» Reduced Defect Rate
» Parent Metal Chemistry
» Simplifies Dissimilar Alloy
Welding
» Fewer Process Variables
» Eliminates Consumables
» Reduces Health Hazard
» Reduced Part Count
» Reduced Production
Time
» Reduced Defect Rates
» Increase in Load
Carrying Capability»
Improved Fracture
Performance
» Eliminates Consumables
» Less Operator
Dependent