Trabalhos futuros

1) Realizar ensaios com lubrificantes distintos e atmosfera controlada; 2) Aprimorar aquisição de dados do NPS;

3) Aprimorar a equação da vida em serviço para incluir parâmetros de velocidade de deslizamento, pressão de contato, bem como considerar flutuações da curva de desgaste;

4) Investigar o desgaste ao uniformizar a superfície dos corpos de prova e investigar a influência de diferentes tipos de acabamento do contra corpo.

6 Referências

ADERIKHA, V. N.; SHAPOVALOV, V. A. Mechanical and tribological behavior of PTFE-polyoxadiazole fiber composites. Effect of filler treatment. Wear, v.

271, n. 5–6, p. 970–976, 2011. Disponível em:

<http://dx.doi.org/10.1016/j.wear.2011.04.011>.

BAHADUR, S.; TABOR, D. The wear of filled polytetrafluoroethylene. Wear, v. 98, n. C, p. 1–13, 1984.

BLANCHET, T. A.; KENNEDY, F. E. Sliding wear mechanism of polytetrafluoroethylene (PTFE) and PTFE composites. Wear, v. 153, n. 1, p. 229– 243, 1992.

CALLISTER JR, William D. Ciência Engenharia de Materiais - Uma

Introdução. [S.l.]: LTC, 2012.

Chemical compositions of AISI (ASTM/ASME) and UNS austenitic stainless steel grades. Disponível em: <https://www.bssa.org.uk/topics.php?article=183>.

Acesso em: 15 jul. 2018.

CONTE, M.; IGARTUA, A. Study of PTFE composites tribological behavior.

Wear, v. 296, n. 1–2, p. 568–574, 2012. Disponível em: <http://dx.doi.org/10.1016/j.wear.2012.08.015>.

DEMIRCI, Mehmet Turan; DÜZCÜKOǦLU, Hayrettin. Wear behaviors of Polytetrafluoroethylene and glass fiber reinforced Polyamide 66 journal bearings.

Materials and Design, v. 57, p. 560–567, 2014.

FERNANDES, Roberto Klecius Mendonça. Avaliação tribológica de

compósitos de PTFE e rejeito de scheelita aplicáveis a mancais secos. 2017. 140 f.

Tese (Doutorado em Engenharia Mecânica) - Programa de Pós-Graduação em Engenharia Mecânica. Universidade Federal do Rio Grande do Norte, 2017.

Freudenberg enters production of PTFE seals for aerospace applications.

Sealing Technology, v. 2017, n. 8, p. 16, 2017. Disponível em: <http://linkinghub.elsevier.com/retrieve/pii/S1350478917302854>.

Processing Technology, v. 123, n. 1, p. 133–145, 2002.

GU, Dapeng et al. Tribological properties of hybrid PTFE/Kevlar fabric composite in vacuum. Tribology International, v. 103, p. 423–431, 2016. Disponível em: <http://dx.doi.org/10.1016/j.triboint.2016.08.004>.

HUTCHINGS., Ian; SHIPWAY, Philip. Tribology: Friction and Wear of Engineering Materials. 2. ed. [S.l.]: Elsevier Ltd, 2017. p. 412.

JIA, Zhining; YANG, Yulin. Self-lubricating properties of PTFE/serpentine nanocomposite against steel at different loads and sliding velocities. Composites Part

B: Engineering, v. 43, n. 4, p. 2072–2078, 2012. Disponível em: <http://dx.doi.org/10.1016/j.compositesb.2012.01.014>.

KRICK, Brandon A. et al. Environmental dependence of ultra-low wear behavior of polytetrafluoroethylene (PTFE) and alumina composites suggests tribochemical mechanisms. Tribology International, v. 51, p. 42–46, 2012. Disponível em: <http://dx.doi.org/10.1016/j.triboint.2012.02.015>.

KRICK, Brandon A. et al. Ultralow wear fluoropolymer composites: Nanoscale functionality from microscale fillers. Tribology International, v. 95, p. 245– 255, 2016.

NASCIMENTO, Alana Rayza Vidal Jerônimo Do. ATRIBUTOS FÍSICOS E

QUÍMICOS DE ÁREAS DEGRADAS PELA MINERAÇÃO DE SCHEELITA NA REGIÃO TROPICAL SEMIÁRIDA. 2015. 90 f. Universidade Federal do Rio Grande

do Norte, 2015.

NEALE, Michael J. The Tribology Handbook. 2. ed. [S.l.]: Butterworth- Heinemann, 1995.

QUAGLINI, Virginio et al. Influence of counterface roughness on friction properties of engineering plastics for bearing applications. Materials and Design, v.

30, n. 5, p. 1650–1658, 2009. Disponível em:

<http://dx.doi.org/10.1016/j.matdes.2008.07.025>.

SAWYER, W. Gregory et al. A study on the friction and wear behavior of PTFE filled with alumina nanoparticles. Wear, v. 254, n. 5–6, p. 573–580, 2003.

SAWYER, W. Gregory et al. Mechanistic Studies in Friction and Wear of Bulk Materials. Annual Review of Materials Research, v. 44, n. 1, p. 395–427, 2014. Disponível em: <http://www.annualreviews.org/doi/10.1146/annurev-matsci-070813- 113533>.

SONG, Fuzhi; WANG, Qihua; WANG, Tingmei. Effects of glass fiber and molybdenum disulfide on tribological behaviors and PV limit of chopped carbon fiber reinforced Polytetrafluoroethylene composites. Tribology International, v. 104, p. 392–401, 2016.

SOUZA, Juliana Ricardo De. Desenvolvimento de compósitos tribologicamente eficazes. 2015. 192 f. Tese (Doutorado em Engenharia Mecânica) -

Programa de Pós-Graduação em Engenharia Mecânica. Universidade Federal do Rio Grande do Norte, 2015.

TOUMI, S.; FOUVRY, S.; SALVIA, M. Prediction of sliding speed and normal force effects on friction and wear rate evolution in a dry oscillating-fretting PTFE/Ti- 6Al-4V contact. Wear, v. 376–377, p. 1365–1378, 2017. Disponível em: <http://dx.doi.org/10.1016/j.wear.2017.02.021>.

TZANAKIS, I. et al. Experimental and analytical thermal study of PTFE composite sliding against high carbon steel as a function of the surface roughness, sliding velocity and applied load. Wear, v. 303, n. 1–2, p. 154–168, 2013.

ÜNLÜ, B. S. et al. Microstructural Properties of Particle-Reinforced Polytetrafluoroethylene Composite Bearings After Wear. Materials Science, v. 51, n. 2, p. 194–199, 2015. Disponível em: <http://link.springer.com/10.1007/s11003-015- 9828-6>.

VIEIRA, Gabriel Marinho et al. INFLUÊNCIA DA PRESSÃO DE CONTATO E VELOCIDADE DE DESLIZAMENTO NO ESTUDO TRIBOLÓGICO DE UM COMPÓSITO À BASE DE PTFE. 2018, Salvador - Bahia: Congresso Nacional de Engenharia Mecânica, 2018.

XU, Jianguang; YAN, Hanbing; GU, Daguo. Friction and wear behavior of polytetrafluoroethene composites filled with Ti3SiC2. Materials and Design, v. 61, p. 270–274, 2014. Disponível em: <http://dx.doi.org/10.1016/j.matdes.2014.04.069>.

YAMANE, M.; STOLARSKI, T. A.; TOBE, S. Wear and friction mechanism of PTFE reservoirs embedded into thermal sprayed metallic coatings. Wear, v. 263, n. 7–12 SPEC. ISS., p. 1364–1374, 2007.

YUAN, Y. et al. MgTiO3filled PTFE composites for microwave substrate applications. Materials Chemistry and Physics, v. 141, n. 1, p. 175–179, 2013.

7 Apêndice

APÊNDICE A – Código utilizado para linearização dos pontos do NPS

function m=media (x)

m = sum(x)/length(x); endfunction

function [A] = calculo1 (prms)

x = read ('pontos1.txt',-1, 1) //Leitura dos pontos

prs = length(x)/prms; //Cálculo de equalização

for (i=1:round(prs)-1) for (j=1:prms)

y(j) = x((i-1)*prms+j)

end

sr(i) = media(y); //armazenamento dos valores médios

end

A = sr

filename = fullfile("pontoslinearizados1.txt")

plot (A)

csvWrite (A, filename) //exportar arquivos em um arquivo txt

endfunction function [B] = calculo2 (prms) x = read ('pontos2.txt',-1, 1) prs = length(x)/prms; for (i=1:round(prs)-1) for (j=1:prms) y(j) = x((i-1)*prms+j) end sr(i) = media(y); end B = sr

filename = fullfile("pontoslinearizados2.txt")

plot (B) csvWrite (B, filename) endfunction function [C] = calculo3 (prms) x = read ('pontos3.txt',-1, 1) prs = length(x)/prms; for (i=1:round(prs)-1) for (j=1:prms) y(j) = x((i-1)*prms+j) end sr(i) = media(y); end C = sr

filename = fullfile("pontoslinearizados3.txt")

plot (C)

csvWrite (C, filename)

function [D] = calculo4 (prms) x = read ('pontos4.txt',-1, 1) prs = length(x)/prms; for (i=1:round(prs)-1) for (j=1:prms) y(j) = x((i-1)*prms+j) end sr(i) = media(y); end D = sr

filename = fullfile("pontoslinearizados4.txt")

plot (D)

csvWrite (D, filename)

APÊNDICE B – Código utilizado para o cálculo RMS da aceleração

function m=rms (x)

m = sqrt((1/length(x))*sum(x^2)); //Cálculo do valor RMS

endfunction

function [A] = calculo1 (prms)

x = read ('ponto1.txt',-1, 1) //Leitura dos pontos

prs = length(x)/prms; //Cálculo de equalização

for (i=1:round(prs)-1) for (j=1:prms)

y(j) = x((i-1)*prms+j) end

sr(i) = rms(y);//Armazenamento dos valores RMS

end

A = sr

filename = fullfile("pontoconvertido1.txt")

plot (A)

csvWrite (A, filename) //exportar os pontos em um arquivo txt

endfunction function [B] = calculo2 (prms) x = read ('ponto2.txt',-1, 1) prs = length(x)/prms; for (i=1:round(prs)-1) for (j=1:prms) y(j) = x((i-1)*prms+j) end sr(i) = rms(y); end B = sr

filename = fullfile("pontoconvertido2.txt")

plot (B) csvWrite (B, filename) endfunction function [C] = calculo3 (prms) x = read ('ponto3.txt',-1, 1) prs = length(x)/prms; for (i=1:round(prs)-1) for (j=1:prms) y(j) = x((i-1)*prms+j) end sr(i) = rms(y); end C = sr

filename = fullfile("pontoconvertido3.txt")

plot (C)

csvWrite (C, filename) endfunction

function [D] = calculo4 (prms) x = read ('ponto4.txt',-1, 1) prs = length(x)/prms; for (i=1:round(prs)-1) for (j=1:prms) y(j) = x((i-1)*prms+j) end sr(i) = rms(y); end D = sr

filename = fullfile("pontoconvertido4.txt")

plot (D)

csvWrite (D, filename) endfunction