Optimising Sintering in Metal Injection Moulding Using In Situ Neutron Diffraction

2012 ◽  
Vol 706-709 ◽  
pp. 1737-1742 ◽  
Author(s):  
D.J. Goossens ◽  
R.E. Whitfield ◽  
A.J. Studer

The phase evolution during the sintering of metal injection moulded stainless steel, 316Land 17-4PH, has been observed using in situ neutron diffraction and Rietveld analysis. The formationof the ferrite phase in the final product is associated with the production of -ferrite at high temperatures.Coexistence of phases at high temperature is thought to allow the segregation of alloyingelements, stabilising the ferrite to lower temperature. To prevent ferrite in the final products the sinteringmust occur at a lower temperature than that at which -ferrite is formed. An alternative regimeis proposed in which the temperature would be cycled around the formation temperature of -ferrite.

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Přemysl Beran ◽  
Debashis Mukherji ◽  
Pavel Strunz ◽  
Ralph Gilles ◽  
Markus Hölzel ◽  
...  

In situ neutron diffraction measurements were performed during heating to high temperature and cooling for a Co-17Re-23Cr-25Ni alloy. The allotropic transformation of the Co matrix and the evolution of the low-temperature hexagonal and high-temperature cubic Co phases were studied. A surprising observation was the splitting of the face-centred cubic (fcc) Co phase peaks at high temperature during heating as well as cooling. The phase evolution was monitored, and an appearance of the secondary fcc phase could be linked to the formation of σ phase (Cr2Re3 type) associated with a compositional change in the matrix due to diffusion processes at high temperature.


Crystals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 360 ◽  
Author(s):  
Dunji Yu ◽  
Yan Chen ◽  
Lu Huang ◽  
Ke An

Real-time in situ neutron diffraction was used to characterize the crystal structure evolution in a transformation-induced plasticity (TRIP) sheet steel during annealing up to 1000 °C and then cooling to 60 °C. Based on the results of full-pattern Rietveld refinement, critical temperature regions were determined in which the transformations of retained austenite to ferrite and ferrite to high-temperature austenite during heating and the transformation of austenite to ferrite during cooling occurred, respectively. The phase-specific lattice variation with temperature was further analyzed to comprehensively understand the role of carbon diffusion in accordance with phase transformation, which also shed light on the determination of internal stress in retained austenite. These results prove the technique of real-time in situ neutron diffraction as a powerful tool for heat treatment design of novel metallic materials.


2009 ◽  
pp. 2556 ◽  
Author(s):  
Florent Tonus ◽  
Mona Bahout ◽  
Paul F. Henry ◽  
Siân E. Dutton ◽  
Thierry Roisnel ◽  
...  

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