Friction plug repair welding of glass fiber-reinforced polyamide 6: Investigation of morphology, microstructure, and mechanical properties

2020 ◽  
Vol 39 (21-22) ◽  
pp. 805-816
Author(s):  
Yinfei Yan ◽  
Yifu Shen ◽  
Keyu Shi ◽  
Jiaxin Wu ◽  
Jinpeng Hu

Friction plug repair welding technology has been demonstrated to be effective to repair the glass fiber-reinforced polyamide 6 sheets in the present paper. Influences of repair hole geometries and parameters on joint morphology and mechanical performance were investigated. Results showed that defect-free repaired joints were produced with the utilization of tapered holes rather than cylindrical holes. Process parameters exerted significant influences on the cross-sectional profile and morphology of the joints. Defect-free repaired welds with larger stir zone thicknesses were produced with the proper increase of rotational speeds, but excessive rotational speeds caused the formation of cavities along the plug boundary and the reduction of stir zone thicknesses. The fluctuation of the wavy bottom interface increased under larger plunge rates and incomplete connections between stir zone and base material were observed under plunge rate of 25 mm/min. Extended dwell time led to larger stir zone thickness and improved joint morphology. Tensile tests showed that the strength of the repaired joints increased and then decreased with the enlargement of rotational speeds. Decreased plunge rate and extended dwell time led to promoted joint mechanical performance. Three failure modes were observed, which corresponded to low, middle, and high repaired weld strengths.

2014 ◽  
Vol 1033-1034 ◽  
pp. 916-920 ◽  
Author(s):  
Hai Shan Tang ◽  
Yi Lun Tan ◽  
Ning Ping Wang ◽  
Lang Ping Xia ◽  
Jie Zhu ◽  
...  

Aluminum hypophosphite can be used to flame retard glass fiber reinforced polyamide 6 (GFPA6). TGIC microcapsulated AlHP (T-AlHP) and epoxy resin microcapsulated AlHP (E-AlHP) were made and put into GFPA6. The vertical burning tests and mechanical tests were taken to study the flame retardant performance and mechanical properties of the corresponding composites. Addition of either T-AlHP or E-AlHP resulted in an increased UL-94 rating and a decreased comprehensive mechanical performance. T-AlHP endowed GFPA6 a better flame retardancy than E-AlHP did. TG showed the decomposition behaviors of T-AlHP, E-AlHP, and the corresponding composites. From Py-GC/MS, the detailed pyrolysis products of flame retardants and the flame-retardant composites were identified. Finally, the properties and mechanism of flame retarded GFPA6 with these two kinds of microcapsulated Aluminum Phosphate were summarized.


Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1041 ◽  
Author(s):  
Francisco J. Alonso-Montemayor ◽  
Quim Tarrés ◽  
Helena Oliver-Ortega ◽  
F. Xavier Espinach ◽  
Rosa Idalia Narro-Céspedes ◽  
...  

Automotive and industrial design companies have profusely used commodity materials like glass fiber-reinforced polypropylene. These materials show advantageous ratios between cost and mechanical properties, but poor environmental yields. Natural fibers have been tested as replacements of glass fibers, obtaining noticeable tensile strengths, but being unable to reach the strength of glass fiber-reinforced composites. In this paper, polyamide 6 is proposed as a matrix for cellulosic fiber-based composites. A variety of fibers were tensile tested, in order to evaluate the creation of a strong interphase. The results show that, with a bleached hardwood fiber-reinforced polyamide 6 composite, it is possible to obtain tensile strengths higher than glass-fiber-reinforced polyolefin. The obtained composites show the existence of a strong interphase, allowing us to take advantage of the strengthening capabilities of such cellulosic reinforcements. These materials show advantageous mechanical properties, while being recyclable and partially renewable.


2022 ◽  
Vol 7 (1) ◽  
Author(s):  
Tao Jiang ◽  
Xinfeng Wu ◽  
Yuan Gao ◽  
Ying Wang ◽  
Ke Yang ◽  
...  

2022 ◽  
Author(s):  
Chunhua Wang ◽  
Yingwei Zhang ◽  
Yong Yi ◽  
Dengwang Lai ◽  
Jun Yang ◽  
...  

2019 ◽  
Vol 37 (3) ◽  
pp. 193-212
Author(s):  
Xi Cheng ◽  
Jianming Wu ◽  
Chenguang Yao ◽  
Guisheng Yang

This study compared thermal degradation, pyrolysis behavior, and the fire behavior of flame-retarded glass-fiber-reinforced polyamide 6 with aluminum hypophosphite and aluminum phenylphosphinate (BPA-Al), respectively. We sythesize aluminum phenylphosphinate by benzenephosphinic acid (BPA) and AlCl3.6H2O in water. so we call aluminum phenylphosphinate BPA-Al for short. The dependence of limiting oxygen index on phosphorus content was linear for aluminum hypophosphite and BPA-Al. Thermogravimetric analysis proved aluminum hypophosphite was less stable than BPA-Al. Thermogravimetric-Fourier transform infrared tests showed that aluminum hypophosphite system balanced the charring process and the gas releasing well, and that BPA-Al system enhanced the charring process and decreased the gas releasing. Peak heat release rate and total heat release data proved that aluminum hypophosphite system was superior to BPA-Al system in lowering the heat release. Their differences were caused by different P-H (aluminum hypophosphite) and P-phenyl (BPA-Al) structures. P-H structure did better than P-phenyl structure in balancing the condensed phase effect and the gaseous phase action. So P-H structure (aluminum hypophosphite) was more suitable than P-phenyl structure (BPA-Al) in the flame retardancy of glass-fiber-reinforced polyamide 6.


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