Non-isothermal Crystallisation Behaviour of a Cr–Fe–Ni–Co–Mo–Si Amorphous Coating

2021 ◽  
pp. 103094
Author(s):  
Tao Ma ◽  
Peng Song ◽  
Quan Dong ◽  
Jun Tan ◽  
Taihong Huang ◽  
...  
Keyword(s):  
Amorphous Coating ◽  
Crystallisation Behaviour ◽  
Isothermal Crystallisation

Influence of Flame Retardant and Glass Fibre on Non-Isothermal Crystallisation Behaviour of Pa66

2007 ◽  
Vol 15 (6) ◽  
pp. 481-487
Author(s):  
Liping Li ◽  
Bin Li ◽  
Fei Tang
Keyword(s):  
Flame Retardant ◽  
Glass Fibre ◽  
Avrami Equation ◽  
Scanning Calorimetry ◽  
Crystallisation Behaviour ◽  
Twin Screw ◽  
Flame Retarded ◽  
Glass Fibre Reinforced ◽  
Isothermal Crystallisation ◽  
Crystallisation Rate

The authors studied the influence of melamine polyphosphate flame-retardant (MPP-FR) and glass fibre on the non-isothermal crystallisation behaviour of a polyamide (PA66) by differential scanning calorimetry (DSC). The glass fibre reinforced PA66 (PA66/GF) and its reinforced flame retarded equivalent (PA66/GF/FR) were prepared using a twin-screw extruder. The experimental results demonstrated that the MPP-FR increased the crystallisation rate and decreased the supercooling required for crystallising nucleation. The glass fibres increased the crystallisation rate and the amount of supercooling. Avrami analysis showed that the non-isothermal crystallisation of PA66 and its composites followed the Avrami equation. The activation energy for the transport of macromolecular segments to the growing surface was calculated by using the Kissinger method based upon DSC data, and the calculated activation energies were 243.5 kJ·mol−1, 201.1 kJ·mol−1 and 305.9 kJ·mol−1 for PA66, PA66/GF and PA66/GF/FR, respectively. The activity of nucleation for GF and MPP-FR were 0.87 and 0.79 respectively, calculated by Dobreva's method. The results indicate that the MPP-FR has more effective ability to promote heterogeneous nucleation than GF.

scholarly journals Non-Isothermal Crystallisation Kinetics of Carbon Black- Graphene-Based Multimodal-Polyethylene Nanocomposites

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 110 ◽  
Author(s):  
Ibrahim Ahmad ◽  
Hyun-Kyung Kim ◽  
Suleyman Deveci ◽  
R. Kumar
Keyword(s):  
Carbon Black ◽  
High Density Polyethylene ◽  
Crystal Surface ◽  
Nucleating Agent ◽  
High Density ◽  
Crystallisation Kinetics ◽  
Crystallisation Behaviour ◽  
Graphene Content ◽  
Isothermal Crystallisation ◽  
Kinetics Of

The effect of carbon black (CB) and microwave-induced plasma graphene (g) on the crystallisation kinetics of the multimodal high-density polyethylene was studied under non-isothermal conditions. The non-isothermal crystallisation behaviour of the multimodal-high-density polyethylene (HDPE), containing up to 5 wt.% graphene, was compared with that of neat multimodal-HDPE and its carbon black based nanocomposites. The results suggested that the non-isothermal crystallisation behaviour of polyethylene (PE)-g nanocomposites relied significantly on both the graphene content and the cooling rate. The addition of graphene caused a change in the mechanism of the nucleation and the crystal growth of the multimodal-HDPE, while carbon black was shown to have little effect. Combined Avrami and Ozawa equations were shown to be effective in describing the non-isothermal crystallisation behaviour of the neat multimodal-HDPE and its nanocomposites. The mean activation energy barrier (ΔE), required for the transportation of the molecular chains from the melt state to the growing crystal surface, gradually diminished as the graphene content increased, which is attributable to the nucleating agent effect of graphene platelets. On the contrary, the synergistic effect resulting from the PE-CB nanocomposite decreased the ΔE of the neat multimodal-HDPE significantly at the lowest carbon black content.

Deposition and Crystallisation Behaviour of Amorphous Silicon Thin Films Obtained by Pyrolysis of Disilane Gas at Very Low Pressure

1994 ◽  
Vol 345 ◽  
Author(s):  
T. Kretz ◽  
D. Pribat ◽  
P. Legagneux ◽  
F. Plais ◽  
O. Huet ◽  
...  
Keyword(s):  
Activation Energy ◽  
Growth Rate ◽  
Amorphous Silicon ◽  
Vapor Deposition ◽  
Electrical Conductance ◽  
Chemical Vapor ◽  
Crystalline Fraction ◽  
Silicon Thin Films ◽  
Crystallisation Behaviour

AbstractHigh purity amorphous silicon layers were obtained by ultrahigh vacuum (millitorr range) chemical vapor deposition (UHVCVD) from disilane gas. The crystalline fraction of the films was monitored by in situ electrical conductance measurements performed during isothermal annealings. The experimental conductance curves were fitted with an analytical expression, from which the characteristic crystallisation time, tc, was extracted. Using the activation energy for the growth rate extracted from our previous work, we were able to determine the activation energy for the nucleation rate for the analysed-films. For the films including small crystallites we have obtained En ∼ 2.8 eV, compared to En ∼ 3.7 eV for the completely amorphous ones.

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