Botany

Micrasterias
fimbriata

BA410

PlanFluar 10x

Moticam 10
Botany

Crystals in
Larix decidua

BA410E

PlanApo 40x
pol. lam.

Moticam 10 stack
Zoology

Parnassius apollo
part of wing

BA310E

PlanApo 20x

Moticam 10 stack
Histology

Femur cross
section

BA310E

PlanApo 20x

Moticam 10
Pathology

Haemolysis
streptococcus
sepsis

BA410

PlanAchro 100x o.i.

Moticam 5
Microbiology

Onion mitosis

BA410 

PlanAchro 60x

Moticam 5
Zoology

Barnacle on
mussel

SMZ-171

Stereo

Moticam 10 stack
General

Tumbled gems

SMZ-171

Stereo

Moticam 10 stack
Pathology

Eimeria stiedae
in liver

BA410 
PlanFluar 20x

Moticam 10
Microbiology

Penicillium with
conidiophores

BA310E

PlanApo

Moticam 10
Histology

Artery

BA410

PlanAchro 10X

Moticam 5
General

Urea crystals

BA410

PlanFluar 20x
pol lam

Moticam 10

What’s in a weld? 

  • 1weldvickers
  • 1HAZ
  • 1welding
Investigation of welded materials for various applications in industry is of paramount importance. There are various test methods available to test the quality of welds such as destructive methods and methods whereby the material remains undamaged such as the use of images created by Rontgen rays.

The picture below shows a sample of a steel weld sample embedded in a polymer, where after it has been ground, polished and etched. In this way the crystal structure and the hardness of the weld itself and the connecting zone between the weld and the parent material can be investigated under the microscope and with a Vickers test apparatus.

With the ‘Motic Images’ software the length of the diagonals of the ground plane of the Vickers imprints have been measured. From their square length ratio it shows that the hardness of the weld is about 12% higher than that of the parent material. Optically there is also a clear difference in the crystal structure of the parent material and the material of the weld. Both crystal structures run smoothly into each other, which is shown on one of the microscopic images. Welds are often "normalized" by means of a heat treatment in order to get back the original crystal structure and reduce welding stresses.
metal99
A steel weld sample prepared for microscopic and hardness examination
With thanks to: Gerard Janssen and Rijk Koster, mechanical engineers


How does it look after 4 years at about 1200 oC

  • Haynes alloy SMZ Mot10
  • Haynes alloy50
  • 1Haynes alloy SMZ
The pictures taken with the SMZ-171, the Motic EPI-Illuminator and the Moticam 10+, are showing a Haynes alloy component which has been exposed to a temperature of about 1200 oC during a period of 4 years. The component was positioned in a naphtha cracking oven (methane fuel side) of a chemical ethylene plant. On the surface of the component that is affected greatly, carburization and crystal formation can be seen. By means of ultrasonic thickness measurement it can be checked if sufficient unaffected material is left under the carburized layer, in order to see if the component is still strong enough.

Haynes 230 alloy is a nickel-chromium-tungsten-molybdenum alloy that combines excellent high-temperature strength, outstanding resistance to oxidizing environments up to 2100°F (1149°C) for prolonged exposures, premier resistance to nitriding environments, and excellent long-term thermal stability. It is readily fabricated and formed, and is castable. Other attractive features include lower thermal expansion characteristics than most high-temperature alloys, and a pronounced resistance to grain coarsening with prolonged exposure to high temperatures.

 metal98ametal98b
Rod material out of Haynes alloy Exposed Haynes alloy piping distance piece

Haynes alloy 230 is composed of Ni 57%, Cr 22%, Tu 14% and Fe < 3%

With thanks to: Gerard Janssen and Rijk Koster, mechanical engineers