The enhancement effect and kinetics of rare earth assisted salt bath nitriding

2016 ◽  
Vol 688 ◽  
pp. 350-356 ◽  
Author(s):  
Mingyang Dai ◽  
Chaoyu Li ◽  
Jing Hu
2019 ◽  
Vol 484 ◽  
pp. 610-615 ◽  
Author(s):  
Tiantian Peng ◽  
Mingyang Dai ◽  
Wei Cai ◽  
Wei Wei ◽  
Kunxia Wei ◽  
...  

2016 ◽  
Vol 34 (2) ◽  
pp. 128-131 ◽  
Author(s):  
Y. S. Zhu ◽  
W. Z. Lu ◽  
D. W. Zuo ◽  
D. W. Cao

2019 ◽  
Vol 61 (5) ◽  
pp. 953
Author(s):  
А.В. Михеев ◽  
Б.Н. Казаков

AbstractThe regression analysis of the rise kinetics of up-conversion luminescence of the LiY_0.8Yb_0.2F_4:Tm^3+ (0.2 at %) crystal is performed. The kinetics curve is obtained with rectangular pulsed excitation by radiation from a laser diode (IR LD) with a wavelength of λ_ p = 933 nm. The most important—in these experimental conditions—mechanisms of the energy transfer from Yb^3+ ions to Tm^3+ ions are established, which are responsible for the transitions between the ground ^3 H _6 and excited ^3 F _4, ^3 H _4, ^1 G _4, ^1 D _2, and ^1 I _6 terms of the Tm^3+ ions. The durations of the relevant energy transfer processes are determined. It is shown that the energy transfer between rare earth ions in the LiY_0.8Yb_0.2F_4:Tm^3+ (0.2 at %) crystal occurs through the dipole–dipole interactions.


2020 ◽  
Vol 26 (1) ◽  
pp. 4-6
Author(s):  
Xiliang LIU ◽  
Changjun MAO ◽  
Meihong WU ◽  
Wei CAI ◽  
Mingyang DAI ◽  
...  

In this study, salt bath nitriding was carried out at 565℃ for various times for 304 stainless steel (304SS). The effect of salt bath nitriding time on the microstructure, micro-hardness and wear resistance was investigated systematically. The results showed a nitriding layer was formed during salt bath nitriding, and the thickness of effective hardening layer is duration dependant. The maximum microhardness value of 1200HV0.01 was obtained at optimal duration of 150min, which was five times higher than that of the untreated sample. And the wear resistance could be significantly improved by salt bath nitriding, the lowest weight loss after wear resistance was obtained while nitriding for 150min, which was one tenth of that of untreated sample.


2016 ◽  
Vol 22 (3) ◽  
pp. 188
Author(s):  
Elhadj Ghelloudj ◽  
Hamid Djebaili ◽  
Mohamed Tahar Hannachi ◽  
Abdenour Saoudi ◽  
Bilal Daheche

<span>The aim of  this paper is to study and analyze the effects of a surface controlled salt bath nitriding on the microhardness of AISI 1045 steel. The nitriding process were implemented in salt bath component at ten different times (from 1 h to 10 h) when temperature was constant at (520ºC). The nitriding process repeated of another specimens at the same times but the temperature was (580ºC).The microstructure of surface layers was investigated by optical microscopy. Hardness profiles were measured with low-load hardness testing to determine the growth of the case depth after nitriding. Microhardness testing was carried out on samples to investigate the hardness profile at the transition from the compound to the diffusion layer. The microhardness of surface of nitrided sample at 520ºC and 580ºC was observed in the range of 318–430 HV0.3 and 329–421 HV0.3, respectively. Experimental results showed that the nitrides ε-Fe2-3(N,C) and γ’-Fe4(N,C) present in the compound layer increase the microhardness. It is found that salt bath nitriding parameters (time and temperature) improves the microhardness. </span>


2003 ◽  
pp. 185-191

Abstract Problems often occur during nitriding, just as with any other heat-treatment process. They can take the form of process problems, steel problems, and machining problems. Troubleshooting is a process of elimination and plain detective work. One must be both observant and systematic during the troubleshooting procedure. This chapter discusses the procedure for troubleshooting problems with gas nitriding, salt bath nitriding, and ion nitriding.


Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 228
Author(s):  
Yuhua Xu ◽  
Zhenghou Zhu ◽  
Hui Zhao ◽  
Jia Zhou

In this paper, a single phase ε-Fe(Si)3N powder was successfully synthesized through the salt bath nitriding reaction method. The flaky FeSi alloy powder was used as the iron source, and non-toxic CO(NH2)2 was used as the nitrogen source. The nitridation mechanism, the preparation technology, the soft magnetic properties, and the magnetization temperature dependence of the powder were studied. The research result showed that ε-Fe(Si)3N alloy powders were synthesized in a high temperature nitrification system after the surface of flaky FeSi alloy powders were activated by a high-energy ball mill. The optimum nitriding process was nitridation for 1 h at 550 °C. The ε-Fe(Si)3N powder had good thermal stability at less than 478.8 °C. It was shown that ε-Fe(Si)3N powder has good soft magnetic properties, and the saturation magnetization of the powder was up to 139 emu/g. The saturation magnetization of ε-Fe(Si)3N powder remains basically constant in the temperature range of 300–400 K. In the temperature range of 400–600 K, the saturation magnetization decreases slightly with the increase of temperature, indicating that the magnetic ε-Fe(Si)3N powder has good magnetization temperature dependence.


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