Post-heating

Post-heat treatment of glass induces phase separation and crystalliza tion A very precise secondary heat treatment is necessary to develop and control photochromic properties. Glass-ceramics receive a thermal ceramming process that induces crystallization... 

There are several methods available to avoid problems with low discharge temperature. One solution is auxiliary heating. The gas can be heated upstream of the expander this is called pre-heating. The gas can also be heated downstream of the expander, known as post-heating. 

Coating plastics, metals, etc. steps generally involve surface preparation, preheating substrate, powder applications, and post-heating. 

Shi, Y. Jin, Z. Li, C. An, H. Qiu, J. 2007. Effects of post-heat treatment on the characteristics of chalcopyrite CuInSe2 film deposited by successive ionic layer absorption and reaction method. Thin Solid Films 515 3339-3343. 

Post heat treatment, when required for pipe components after bending or forming, shall be performed in accordance with para. GR-3.6, including Table GR-3.6.1. 

Fig. 4.4 XRD patterns of Tii-xVxOz samples with x=0.15 post-heated at various temp (Reprinted with permission from Ref. [55])...

The amount and positions (atomic locations) of oxygen atoms in the superconductors are highly critical and determine the properties of the superconductor. The oxygen vacancies (or deficiency) can be ordered in these materials. Neutron-diffraction experiments were required to determine the population parameters and the atomic positions of oxygen in these structures. The superconducting transition temperature in these "ceramic" oxides is a critical balance between the oxygen content and a proper mix of Cu2+ and Cus+ ions generated in the anneal or post-heat treatment. 

In contrast to the dry methods, there are other conventional methods related to post heat treatment from precipitates from the aqueous solutions. The ambient aqueous routes and the hydrothermal methods at elevated temperature usually lead to rare earth precipitates like hydroxides, carbonates, instead of oxides. In fact, the hydrothermal treatment of rare earth oxide powders results in a hydration process to form hydroxides. Subsequently, the precursor could be used to produce rare earth oxide nanocrystals with post annealing at varied temperatures and in appropriate atmosphere. 

Cemented carbide cutting tools, e.g. inserts for turning, can easily be CVD coated without a post heat treatment, because their properties are only slightly influenced by the high CVD temperature. 

Massive steel forming tools or punching tools are also strongly influenced by the high CVD temperature and need a post heat treatment to receive useful properties. But the distortion of these massive tools during post heat treatment can be controlled to a certain extent. 

These soft steel substrates do not sufficiently support the hard coatings under load, therefore they are not useful for a CVD coated forming tool and need to be post heat treated. " Different heat treatment paths of CVD coated steel tools are possible. The most... 

For the characteristic properties two representative examples are chosen the CVD TiN coated and post heat treated high alloy tool steel D2 and the low alloy tool steel L3, both heat treated following path D. The complete heat treatment parameters are ... 

Mechanical Properties and Structure of C VD Coated and Post Heat Treated Steels, Surface and Coatings Technology, 89, 1997, pp.299-304. 

Aluminum powder is frequently added to explosives and propellants to improve their performance. The addition of aluminium results in considerable gain in heat of explosion because of the high heat of formation of aluminia (1658 kJ/mole, 16260 kJ/kg) leading to higher temperatures of the fumes. Aluminium not reacted in the detonation front might be oxidized atmospheric oxygen to induce post-heating in the fume zone and to increase the -> air blast or even to initiate a delayed secondary explosion. 

Entry RX Initial Yield and Ratio (A B) Post-Heating Yield and Ratio (A B)... 

Luo, Cui and Li (1999) addressed the problem of temperature sensitivity of IBAD of ACPs and their subsequent crystallisation forming hydroxyapatite. Post-depositional annealing temperatures were decreased to 400 °C. The crystallisation of calcium phosphate coating is a hydroxyl ion diffusion-controlled process, thought to be the mechanism responsible for the decrease of the crystallisation temperature. The detailed study of the crystallisation process of calcium phosphate coatings shows that the crystallinity of the hydroxyapatite coating can be well controlled by adjusting the post-heat-treatment time. 

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