The study of the superplastic state of eutectics by microhardness testing

1989 ◽  
Vol 8 (1) ◽  
pp. 4-6 ◽  
Author(s):  
F. O. Muktepavel ◽  
I. Manika
2015 ◽  
Vol 63 (3) ◽  
pp. 263-270 ◽  
Author(s):  
Matheus GRANDO ◽  
Lívia Muniz PACHECO ◽  
Daniela Maffei BOTEGA ◽  
Luciana Mayumi HIRAKATA ◽  
Juliana Balbinot HILGERT

Objective: To evaluate the Knoop hardness, composition, and wear resistance of acrylic-resin artificial teeth exposed to mechanical toothbrushing. Methods: Artificial teeth from three commercial brands - Biotone, Trilux, and Soluut PX - were used. From each brand, 10 teeth were selected for wear evaluation after mechanical brushing, 10 for microhardness testing, and 5 for composition analysis. Specimens underwent 55,000 brushing cycles, under a 200-g load and at a frequency of 250 cycles per minute, using a soft-bristled toothbrush (IndicatorPlus 30, Oral-B) soaked in a 1:1 toothpaste/water slurry (Oral B Pró Saúde). Microhardness testing was performed using a 25-g load for 15 seconds in an HMV-2 hardness tester (Shimadzu). The composition of teeth from different brands was determined by scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS) (Jeol JSM 5800). Results: Wear results after mechanical brushing were compared by means of the paired t-test, whereas those obtained in microhardness testing were compared by ANOVA with Bonferroni correction. There was no statistically significant difference between brands in either trial. Conclusion: Composition analysis revealed that all of the artificial teeth analyzed contain carbon and oxygen. Trilux and Soluut PX brand teeth also contain silicon; however, the presence of filler particles did not result in increased resistance.


Mechanika ◽  
2016 ◽  
Vol 22 (2) ◽  
Author(s):  
Saulius Baskutis ◽  
Vytautas Vasauskas ◽  
Audrius Žunda

1985 ◽  
Vol 5 (2) ◽  
pp. 113-136 ◽  
Author(s):  
R.J. Crawford ◽  
G. Stephens

2003 ◽  
pp. 167-183

Abstract Examining and evaluating the nitrided case is generally accomplished by hardness testing and microscopic examination. This chapter discusses both characterization methods, as well as sample preparation. The discussion covers the process, advantages, and disadvantages of these methods. The chapter also discusses the processes involved in the etching of the sample after microhardness testing and provides some practices that contribute to the safe preparation of specimens. Examples of nitrided case microstructures are also presented.


1988 ◽  
Vol 7 (6) ◽  
pp. 641-642 ◽  
Author(s):  
I. P. Manika ◽  
J. J. Maniks ◽  
J. A. Teteris

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