One Minute Mentor: Plasma Nitriding Equipment

Cold-walled (double-walled water-cooled) systems were the first generation of plasma nitriding furnaces. This technology is also a vacuum-based process but employs the principle of glow discharge to provide energy for heating and nitriding at one time. Therefore, the independent control of the temperature stability and the nitriding intensity is not possible because both processes are using the same energy source—the plasma.

The hot-wall plasma nitriding furnaces, the next generation of cold-wall ion nitriding systems, are mainly used and built now. This system ensures optimal nitriding quality by fulfilling the highest demands on temperature and nitriding process control. The big advantage of this technology is the separation of the control of the heating and the plasma nitriding parameters. The heating and temperature control of hot-wall plasma nitriding furnaces is realized by several independent heating/cooling zones, which guarantees optimal temperature homogeneity

For more information, click on the link below (subscription required). Then scroll to Figure 26.

R Schneider; R. Mesquita; H. Altena; T. Müller; P. Seemann, Processes and Furnace Equipment for Heat Treating of Tool Steels, ASM International, 2014, https://doi.org/10.31399/asm.hb.v04d.a0005958

Evolution on the microstructure and mechanical properties of a new multicomponent near-Alpha Titanium Alloy after rolling and heat treatments

Beijing University of Technology, China, presented the microstructure and mechanical properties of a new type of multi-component near-α titanium alloy sheet after rolling, 700°C aging, and 800°C aging in a new paper.

 The results show that the strength of the alloy after aging at 700°C increases from 1156 MPa to 1304 MPa, respectively, but decreases to 1246 MPa with the aging temperature increasing. The ductility of the alloy aged at 700°C is lower than that of the rolled state, but the ductility increases slightly with the aging temperature increasing. The effect of aging heat treatment on the microstructure and precipitation behavior of alloy plates has been studied and compared with alloys before aging. 

After heat treatment, the content of primary α decreases from 25% to 5%, respectively. Two kinds of silicide precipitate at different positions, with the large-size spherical silicide being (Ti, Zr, Nb)5Si3, and the small-size fusiform silicide being (Ti, Zr, Nb)6Si3, respectively. Ti3Al was precipitated in the primary α phase, during the aging process. The silicides exhibit the strengthening effect on the alloy, but the effect weakens when the silicides grow up. The loss in ductility is mainly attributed to the precipitation of the α2 phase after aging treatment. However, ductility is improved after applying higher aging temperatures as the size of the α2 phase becomes smaller, and the distribution of them tends to become dispersed.

Read further here

 

Constellium joins EPA’s Energy Star program as an industrial partner

Constellium, Paris,  announced that they are participating in the U.S. Environmental Protection Agency (EPA) Energy Star program as an Industrial Partner.

The Energy Star program is a voluntary initiative that helps businesses protect the environment by promoting energy-efficient products, homes, buildings and manufacturing plants, as well as save on energy costs. As an Industrial Partner, Constellium will work closely with the EPA to identify and implement energy-saving strategies and technologies across its manufacturing operations in the United States.

Constellium has already taken significant steps to reduce its energy consumption and greenhouse gas emissions. The company has set a target to reduce its greenhouse gas emissions by 30% by 2030 vs 2021, and reports its results annually in its sustainability report. 

https://www.constellium.com/news/constellium-joins-epas-energy-star-r-program-as-an-industrial-partner

One Minute Mentor: Vacuum Furnaces

The demands on vacuum-hardening technology have changed in recent decades. One of the most important considerations that must be met is the accomplishment of highest dimensional stability with optimal microstructural properties and minimal change of the surface of the workpieces. 

Minimizing exposure to air during the heat treatment by reducing the quantity of oxygen in a heat treatment furnace, as with creating a vacuum, is an excellent method for preventing changes in surface appearance and chemical composition.

Suppliers of modern vacuum furnaces are further faced with new demands, such as increasing quenching speed to improve microstructural and mechanical properties by reducing grain size, and enhancing hardness and toughness and/or reducing distortion due to the hardening process. Furthermore, quality standards such as AMS 2750d or North American Die Casting Association (NADCA), which describe temperature homogeneity or quenching speeds and resulting and needed workpiece properties, had a significant effect on furnace design and process control.

For more information, click on the link below (subscription required). Then scroll to Figure 14

R Schneider ; R. Mesquita ; H. Altena ; T. Müller ; P. Seemann,Processes and Furnace Equipment for Heat Treating of Tool Steels, ASM International, 2014, https://doi.org/10.31399/asm.hb.v04d.a0005958