The purpose of this study is to evaluate the performance of new and reground cemented carbide twist drills considering the variation in the form of regrinding applied to a drill after it reaches its wear limit. The following variables were taken into account: coating material (uncoated, TiAlN and AlCrN) and recoating routine after regrinding (no recoating, recoating over existing coating and recoating after removal of the existing coating). The performance evaluation parameters were tool life, thrust force and torque. The results indicated that the performance of reground drills was generally inferior than that of new drills. Among the coated drills, only TiAlN-coated drills that were stripped (removal of the existing coating), reground and recoated (application of a new TiAlN coating) reached performance values approaching those of new drills. In most of the tests, the uncoated drills produced higher thrust forces and torque, underwent higher wear and had shorter tool lives.
DinizAEMarcondesFCCoppiniNL. Tecnologia da usinagem dos materiais [Materials machining technology]. São Paulo, SP: Editora Artber, 2006 (in Portuguese).
2.
TönshoffHKSpintigW. Machining of holes developments in drilling technology. CIRP Ann: Manuf Techn1994; 43(2): 551–561.
3.
GuesserWL. Propriedades Mecânicas dos Ferros Fundidos [Mechanical properties of cast irons]. 1st ed. São Paulo, SP: Editora Edgar Blucher, 2009 (in Portuguese).
4.
ISO 3685:1993. Tool life with single point turning tools.
5.
MachadoARAbrãoAMCoelhoRT. Teoria da usinagem dos materiais [Theory of materials machining]. 2nd ed.São Paulo, SP: Editora Edgar Blucher, 2011 (in Portuguese).
6.
BakkalMShinhAJMcspaddenSB. Thrust force, torque and tool wear in drilling the bulk metallic glass. Int J Mach Tool Manu2005; 45: 863–872.
7.
CastroP. Aspectos tecnológicos da usinagem a seco com mínima quantidade de fluido de corte na furação com broca helicoidal [Technological aspects of dry milling with MQL in drilling with twist drills]. Dissertação de Mestrado em Engenharia Mecânica [Master’s Dissertation, Mechanical Engineering], Universidade Federal de Santa Catarina—UFSC, Brazil, 2001 (in Portuguese).
8.
TeixeiraC. Influência dos erros geométricos de afiação nas brocas helicoidais de aço rápido na qualidade dos furos produzidos [Influence of regrinding geometric errors in HSS twist drills on the quality of machined holes]. Dissertação de Mestrado do Programa de Pós-Graduação em Eng. Mecânica, [Master’s Dissertation, Mechanical Engineering], Universidade Federal de Santa Catarina—UFSC, Brazil, 1995 (in Portuguese).
9.
BoeiraAMG. Modelagem e simulação das forças na furação com brocas helicoidais a partir de dados obtidos no torneamento de segmentos cilíndricos [Modeling and simulation of cutting forces in drilling with twist drills, using data from turning of cylindrical segments]. Tese de Doutorado em Engenharia Mecânica [PhD Thesis, Mechanical Engineering], Universidade Federal de Santa Catarina, Brazil, 2010 (in Portuguese).
10.
OstronoffH. Recondicionar ao invés de trocar [Reconditioning instead of changing]. São Paulo, SP: Revista O Mundo da Usinagem, 2007, pp.6–11 (in Portuguese).
11.
GodoyJM. Furação profunda no aluminio de aviação com brocas normais [Deep drilling of aeronautic aluminum with standard drills]. Dissertação de Mestrado em Engenharia Mecânica [Master’s Dissertation, Mechanical Engineering], Universidade Federal de Santa Catarina—UFSC, Brazil, 1998 (in Portuguese).
12.
KhabeeryM. Some observations of surface integrity of deep drilling holes. Wear1990; 142: 331–349.
13.
KudlaL. Influence of feed motion features on small holes drilling process. J Mater Process Tech2001; 109: 236–241.
SchroeterRBWeingaertnerWL. Processos de usinagem e ferramentas de corte: Nível 1, Parte 2 [Machining processes and cutting tools: level 1, part 2]. Florianópolis, SC: Laboratório de Mecânica de Precisão—UFSC, 2001 (in Portuguese).
16.
TrentEMWrightPK. Metal cutting vol. 4. 4th ed.Woburn, MA: Butterworths, 2000.
17.
ColdwellHL. The use of soft/lubricating coatings when dry drilling BS L168 aluminium alloy. Surf Coat Tech2004; 177–178: 716–726.
18.
HarrisSGDoyleEDVlasveldAC. A study of the mechanisms of Ti1-xAlxN and Ti1-x-yAlxCryN coated high-speed steel drills under dry machining conditions. Wear2003; 254: 723–734.
19.
FerraresiD. Fundamentos da usinagem dos metais [Fundamentals of metal machining]. São Paulo, SP: Editora Edgard Blücher Ltda, 1977 (in Portuguese).
20.
StemmerCE. Ferramentas de Corte I [Cutting tools I]. 5th ed.Florianópolis, SC: Editora da UFSC, 2001 (in Portuguese).
21.
Ann. Die ratiobohrer und ihre praxisgerechte anwendung (Manufacturing catalog). Albstadt: Gühring, 1997.
22.
ChenYCLiaoYS. Study on wear mechanisms in drilling of Inconel 718 superalloy. J Mater Process Tech2003; 140: 271–273.
23.
WangZM. Advances in precision machining of small deep holes. J Mater Process Tech1997; 68: 257–261.
