Investigation of Chip Deformation and Breaking with a Staggered Teeth BTA Tool in Deep Hole Drilling

The problem of chip breaking and evacuation is the key point of staggered teeth boring and trepanning association (BTA) drilling. The factors that influence chip breaking with staggered teeth BTA deep hole drilling are analyzed by using the chip bending deformation mechanism for chip formation and flow through the rake face and chip breaker. This study investigated the distribution and variation of chip deformation and breaking along drilling conditions, with respect to drilling radius, drilling process parameters, tool wear, and chip breaker geometric parameters. The results show that the tool-chip contact length is about 1.65 times the chip thickness in staggered teeth BTA drilling. The cutting radius of the teeth has a considerable influence on the chip thickness. Compared with the drilling speed, the feed has a greater impact on chip deformation and breaking, and the chip thickness and strain increase with increased feed. Increased drilling depth and tooth wear aggravates the friction state between the chip and the rake face, augments chip thickness and tool-chip contact length, and increases the chip’s strain increment. As the width of chip breaker decreases and the height increases, the chip strain increases and the breaking conditions are improved.

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Application and Technology Research in Deep-Hole Drilling System

Materials Science Forum ◽

10.4028/www.scientific.net/msf.800-801.506 ◽

2014 ◽

Vol 800-801 ◽

pp. 506-510

Author(s):

Hai Yan You ◽

Shu Cai Yang ◽

Cai Xu Yue ◽

Xue Feng Wu ◽

Yang Xie

Keyword(s):

Cutting Speed ◽

High Hardness ◽

High Strength ◽

Cutting Parameters ◽

Hole Drilling ◽

Drilling Process ◽

Deep Hole ◽

Deep Hole Drilling ◽

Chip Breaking ◽

Content Selection

With the new type of high strength , high hardness difficult machining parts appear constantly, both for the quality of deep processing, durability of the tools, or reliability of the drilling systems are putting forward higher requirements. This paper mainly describes the characteristics of deep-hole drilling systems and applications, and content selection of cutting parameters, impact of cutting speed and feed rate for chip breaking and so do some explanation, These have certain guiding significance for chip breaking can get better. Finally, introduce the deep-hole drilling in the drilling process causes common problems and solutions, to provide some references for practical manufacture process.

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Modified DLC-Coated Guide Pads for BTA Deep Hole Drilling Tools

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.438.195 ◽

2010 ◽

Vol 438 ◽

pp. 195-202 ◽

Cited By ~ 4

Author(s):

Dirk Biermann ◽

Nadine Kessler ◽

Thorsten Upmeier ◽

Thomas Stucky

Keyword(s):

Surface Quality ◽

Borehole Wall ◽

Hole Drilling ◽

Drilling Process ◽

Deep Hole ◽

Forming Process ◽

Workpiece Material ◽

Drilling Depth ◽

Deep Hole Drilling ◽

Drilling Tools

The BTA (Boring and Trepanning Association) deep hole drilling process is commonly used to machine boreholes with a large drilling depth-to-diameter ratio (l/D) and outstanding workpiece quality. The asymmetric tool design leads to a nonzero radial component of the cutting force and the passive force, which are conducted to the borehole wall by so-called guide pads. These guide pads smooth the borehole wall by a forming process and improve the surface quality. Processes, that machine materials with a high adhesion tendency, such as high alloy stainless steel, suffer from poor surface quality in the borehole and the adhesion from the workpiece material on the guide pads. In this paper modified Diamond-Like-Carbon (DLC) coated guide pads for BTA deep hole drilling tools are investigated. The scope of the experiments was the reduction of the adhesion by reducing the friction coefficient of the guide pads, as well as the improvement of the quality of the borehole wall.

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Temperature monitoring in the subsurface during single lip deep hole drilling

tm - Technisches Messen ◽

10.1515/teme-2020-0055 ◽

2020 ◽

Vol 87 (12) ◽

pp. 757-767

Author(s):

Robert Wegert ◽

Vinzenz Guski ◽

Hans-Christian Möhring ◽

Siegfried Schmauder

Keyword(s):

Cutting Parameters ◽

Drill Hole ◽

Machining Process ◽

Hole Drilling ◽

Drilling Process ◽

Deep Hole ◽

Machining Processes ◽

Deep Hole Drilling ◽

Feed Force ◽

Cutting Zone

AbstractThe surface quality and the subsurface properties such as hardness, residual stresses and grain size of a drill hole are dependent on the cutting parameters of the single lip deep hole drilling process and therefore on the thermomechanical as-is state in the cutting zone and in the contact zone between the guide pads and the drill hole surface. In this contribution, the main objectives are the in-process measurement of the thermal as-is state in the subsurface of a drilling hole by means of thermocouples as well as the feed force and drilling torque evaluation. FE simulation results to verify the investigations and to predict the thermomechanical conditions in the cutting zone are presented as well. The work is part of an interdisciplinary research project in the framework of the priority program “Surface Conditioning in Machining Processes” (SPP 2086) of the German Research Foundation (DFG).This contribution provides an overview of the effects of cutting parameters, cooling lubrication and including wear on the thermal conditions in the subsurface and mechanical loads during this machining process. At first, a test set up for the in-process temperature measurement will be presented with the execution as well as the analysis of the resulting temperature, feed force and drilling torque during drilling a 42CrMo4 steel. Furthermore, the results of process simulations and the validation of this applied FE approach with measured quantities are presented.

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