Analysis of form threads using fluteless taps in cast magnesium alloy (AM60)

Carvalho, Alessandra Olinda de; Brandão, Lincoln Cardoso; Panzera, Túlio Hallak; Lauro, Carlos Henrique

doi:10.1016/j.jmatprotec.2012.03.018

Cited by 47 publications

(21 citation statements)

References 7 publications

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“…However, the imperfection at the minor diameter typical of formed threads (thread peaks), so-called claws or split crest (Figure 1(b)), has no direct influence on the thread or screw strength. 26 FT is feasible in ferrous and non-ferrous metals if hardness and tensile strength are not above 200 HBN and 800 MPa, respectively. It strengthens material on thread flanks, in particular in the thread root area, and the strain hardening effect has a positive influence on the overall strength of fasteners and screw joints under dynamic stresses, as demonstrated.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Combination of friction drilling and form tapping processes on dissimilar materials for making nutless joints

Urbikaín

Pérez²,

Lacalle

et al. 2016

Proceedings of the Institution of Mechanical Engineers, Part B:

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In this article, a new method for the rapid and economical production of 'nutless' bolted joins is presented, using a combination of two hole-making techniques, namely, form drilling and form tapping. The combined method achieves a quick way for the production of threaded holes on couples of dissimilar metal alloys, as it is the case of steels and aluminium alloys. After the simultaneous form drilling on the aluminium-steel pairs and followed by form tapping, a fastener can be introduced and screwed for achieving a tight bolted joint, without any necessity of nut. However, form drilling and threading are performed consecutively in the same machine tool, reducing the whole process time. The process parameters were studied for reducing the gap between surfaces and producing a good cup for making the posterior threading. Then, mechanical testing of several test pieces resulted in a similar behaviour than traditional bolted joints. Finally, corrosion tests were performed for a better understanding of the joint manufactured. In this way, savings in time and money are derived from the application of the approach. Target markets for the new approach are the light boilermaking industry in order to eliminate either welding beads or classical bolted joints using nuts.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Combination of friction drilling and form tapping processes on dissimilar materials for making nutless joints

Urbikaín

Pérez²,

Lacalle

et al. 2016

Proceedings of the Institution of Mechanical Engineers, Part B:

View full text Add to dashboard Cite

show abstract

“…The material flow and the most influential process parameters were analyzed. De Carvalho et al 15 investigated the effects of the factors on torque, hardness, fill rate, and thrust force of the tapping process in cast magnesium alloy. And the best closure of the split crest was achieved.…”

Section: Introductionmentioning

confidence: 99%

The formation mechanism of protrusion of long thread by axial self-infeed rolling process

Zhang

Fan

Zhang

et al. 2020

Proceedings of the Institution of Mechanical Engineers, Part B:

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In the forming process of long threads by axial self-infeed rolling process, the protrusion generates on the top of the tooth profile, which affects the strength and precision of the formed threads. In this article, the principle of the axial self-infeed rolling process was described, and the finite element model was established to simulate the forming process of threads. The formation mechanism of protrusion was analyzed through material flow, which was verified by experiments. The pre-rolling angle and material’s influence on the protrusion size was also investigated. The results showed that the axial motion of the rollers squeezed one flank of the tooth, leading to higher protrusion on the face side as compared to the other side. During the rolling process, the height of the protrusion increased first and then decreased, reaching the maximum value when the height of the formed tooth was 73% of the whole tooth. In order to reduce the protrusion height, the pre-rolling angle should be 2°.

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“…The severity of the process is smaller when compared to cutting operations due to the lower velocities and temperatures involved. For this reason, tool lifetime and process reliability are higher, which together with the lack of chip formation, make the process attractive for manufacturing, particularly in automotive [1,2]. Despite the industrial relevance of form tapping, the number of scientific works devoted to provide a profound understanding on the process are rather scarce, in particular when compared to other machining and manufacturing processes such as grinding or milling [3].…”

Section: Introductionmentioning

confidence: 99%

Performance of nanolubricants containing MoS2 nanotubes during form tapping of zinc-coated automotive components

Ripoll

Tomala

Totolin

et al. 2019

Journal of Manufacturing Processes

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The paper presents the first use of nanolubricants containing MoS 2 nanotubes for form tapping of zinc-coated steel. MoS 2 nanotubes are known for their superb low frictional, anti-wear and extreme pressure properties and have shown a promising performance as nanolubricant additive in many machining and forming applications. However their interfacial interaction with zinc-coated components commonly used in automotive applications and their synergisms and antagonisms with currently used additives in forming oils are two crucial aspects that have not been addressed so far. The assessment of these synergies is of uttermost importance for developing future nanofluid minimum quantity lubrication formulations, since despite their extraordinary performance, MoS 2 nanotubes are not able to fulfil all the roles expected from a forming oil. To this end, this paper aims to investigate the performance of MoS 2-based nanolubricants in combination with representative forming oil additives. The threads are perform using a form tapping unit with customized data acquisition on zinc-coated steel, as a representative part in automotive applications. The performance of the nanolubricants is thoroughly investigated using advanced analytic methods with the aim of revealing the underlying interface interaction mechanisms for the observed torque behaviour and resulting thread morphology and sub-surface hardness. The results show that MoS 2 nanotubes are able to interact and form a tribofilm in Zn coated surfaces that leads to a superb friction performance. In combination with oil additives, MoS 2 based nanolubricants have a particularly positive synergy with extreme pressure additives in terms of friction reduction, sub-surface hardening and thread morphology. On contrary, the lowest synergy is achieved in the presence of dispersants, leading to higher torques during form tapping and higher sub-surface hardness in the formed threads.

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Analysis of form threads using fluteless taps in cast magnesium alloy (AM60)

Cited by 47 publications

References 7 publications

Combination of friction drilling and form tapping processes on dissimilar materials for making nutless joints

Combination of friction drilling and form tapping processes on dissimilar materials for making nutless joints

The formation mechanism of protrusion of long thread by axial self-infeed rolling process

Performance of nanolubricants containing MoS2 nanotubes during form tapping of zinc-coated automotive components

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