Forces In Broaching Research Articles

High performance machining simulation of curved edge broach with surface material constitutive model and tool-chip friction

Curved edge broaches can significantly improve the machining efficiency and accuracy of key components of aviation engine turbine discs. However, existing constitutive models and friction models fail to describe these parameters accurately during the broaching process. Therefore, this paper proposes modifications to the J-C constitutive model based on the MSG model and the friction model based on the SCG model, which are applied to an Inconel 718 simplified tenon broaching finite element model. The single-stage modification involves modifying the constitutive model first, followed by modifying the friction model from the modified constitutive model to achieve cascade correction. To verify the accuracy of the model, a simplified tenon broaching experiment is conducted, and the predicted broaching force, broaching temperature, and chip morphology are compared with experimental results. In conclusion, the modified constitutive model proposed in this paper has an accuracy of approximately 90 %, which represents a 33.3 % error reduction compared to that of the conventional constitutive model. Furthermore, the accuracy of the cascade modified model proposed in this paper can be nearly 95 %, resulting in an error reduction of about 50 % based on the modified constitutive model. The newly proposed cascade correction model can help optimize tool and process parameters in tenon broaching to achieve the desired broaching force, broaching temperature, and chip morphology using simulation-based optimization.

Broaching force prediction of nickel-based superalloy based on material parameter identification

The broaching process of the nickel-based superalloy determines the aero-engine turbine disc mortises performance; thus, the broaching force should be analyzed principally. The aim of the study is to reveal the material constitutive law for the nickel-based GH4169 alloy broaching force prediction. However, the GH4169 material constitutive model may just be verified by the hot compression tests at the limited high-temperature conditions. The residual stress-based finite element updating (FEU) inverse method was used to optimize the GH4169 material parameters. And the finite element (FE) model for the whole multi-stage processing of the turbine disc billet was simulated with high efficiency and accuracy, where the wide forming temperature range would be the critical factor for the consequent broaching analysis. The cutting conditions were tested to measure the residual stresses in the multi-stage formed GH4169 alloy disc billet by the layer removal method. The objective function (OF) designed with the experimental-numerical residual stresses were optimized successfully. The GH4169 alloy broaching force predicted with the identified thermo-mechanical material constitutive model in this study was satisfied with the validation test results, and the influence of cutting parameters on the broaching force distribution design could be effectively controlled, which could guarantee the high dimensional accuracy and the excellent reliability of the aero-engine turbine disc.

Force model for complex profile tool in broaching Inconel 718

Complex profile broaches are widely used in the manufacture of complex parts of aero-engines, but the forces in the broaching process are difficult to predict and control. A new numerical model for broaching force with complex profile tools was presented, which considered the area and arc length of the curved shear zone boundary. The area and arc length were calculated by the curve function of the boundary, which is firstly predicted by FEM simulation. Then, an experimental device was set up to carry out the broaching experiment with straight profile tools and complex profile tools in accordance with the progressive depth of the cut. Based on the experiments, the traditional broaching model and the modified model with the complex profile tool have been established. Compared with the traditional force model, the accuracy of the modified model has been moderately improved. Furthermore, the modified main broaching force (Y direction) model and the normal force (Z direction) model show a significant improvement in accuracy of 4.8% and 9.7%, respectively, which suggests that the projection area of curved shear zone A1 and the projection arc length of curved shear zone l1 have a big impact on the broaching process. It is firmly believed that the modified model proposed in this paper can provide guidance for the design of complex profile tools and facilitate the efficient and high-precision machining of complex parts.

WITHDRAWN: Effect of Micro-texture of Flank Surface on Broaching Force and Surface Quality of Workpiece

Abstract The application of surface micro-texture in the field of processing tools has become one of the most effective ways to improve economic efficiency in the manufacturing industry. Broaching, as a highly efficient processing method, is widely used in various industries. In order to improve the cutting performance of broaching tools, three types of surface micro-texture were made on the flank face of broach by Nd: YAG laser: (i) pit in the A1 area (5-14 teeth), (ii) groove in the A2 area (15-24 teeth), (iii) V-type in the A3 area (25-34 teeth), respectively. Then, dry broaching experiments were carried out with a micro-texture broach tool (MBT) and the conventional broach tool (CBT) on the built broaching test system. The results show that compared with the CBT, the MBT tool can effectively reduce the broaching force and improve workpiece surface quality. The largest broaching force of the micro-textured teeth with pit is reduced by 6.62%, while the groove and V-type teeth are 4.84% and 5.63%, respectively. The workpiece surface quality of MBT tool is increased 51.87% compare CBT tool processing. This paper proved that the application of micro-texture on broaches can certainly improve processing quality and reduce energy consumption.

Assessment of water-based cutting fluids with green additives in broaching

In order to improve the cutting performance in broaching, the lubrication and cleaning effects offered by water-based cutting fluids with green additives need to be studied from the viewpoint of green manufacturing. Therefore, water-based solutions with castor oil, surfactant (linear alkylbenzene sulfonate, LAS), and nanographite were prepared by ultrasonic agitation and sprayed into the zone of broaching via atomization. The performances of the cutting fluids, in terms of the viscosity, specific heat, wetting angle, and droplet size, were evaluated to discuss their effects on the broaching load. Among the fluids, the addition of LAS into oil-in-water (WO-S), where its cutting fluid with 10 wt.% castor oil and 1.5 wt.% surfactant, exhibited the lowest broaching force. With regard to the lubricating and cleaning mechanisms, WO-S has good wettability and permeability, and hence, can lubricate the cutting edge of the tool to decrease the cutting load, cool the cutting edge to keep it sturdy, and clean the surface of the cutting edge to keep it sharp. The results reveal that the simultaneous addition of castor oil and LAS had remarkable effects on the lubrication and cleaning, and resulted in a broaching load reduction of more than 10% compared to commercial cutting fluids. However, the addition of nanographite could not improve the lubrication owing to its agglomeration.

Experimental Study on the Performance of Hydraulic Vibration Assisted Broaching (HVAB) Based on Piezoelectric Sensors

In order to improve the keyway broaching process and verify the feasibility of vibration-assisted broaching process, an experimental study on a novel hydraulic vibration assisted broaching (HVAB) system with double-valve electro-hydraulic exciter (DVEHE) is proposed in this paper. The performances of HVAB at different excitation frequencies were compared from three aspects: (a) the cutting force under the different vibration frequencies, (b) the surface roughness of the workpiece, and (c) the flank face wear of the tool. For precision on-line measurement of larger broaching forces, four piezoelectric sensors were fixed on the broaching machine. The experimental results show that HVAB can effectively improve the performance of the broaching process, approximately reduce the broaching force by as much as 9.7% compared to conventional broaching (CB) and improve the surface quality of workpiece. Some explanations are offered to support the observations.

Investigation on broaching performance and unloading mechanism of micro-textured broach

A surface textured broach was designed to slow the broach surface wear and increase the lifespan. Laser processing technology was used to generate inverted triangle surface texture on the flank of key way broach. Broaching 45# steel load test was carried out. Using a finite element analysis method, a broaching force model was developed to obtain the internal stress distribution and to analyze the anti-wear unloading mechanism of textured broach. Investigation shows that micro-textured broach can approximately reduce the broaching force by 5 % and improve the response performance of broach for broaching load. The texture slot can effectively unload the concentrated stress of the main function area and prevent fatigue deformation failure by suddenly change of stress, but it has no effect on the rake face boundary. The texture has a greater impact for broaching in the process of extrusion deformation than the process of fracture layered. The textured broach can reduce the tool wear due to the nice wear resistance of inverted triangle texture, significantly improves the cutting efficiency and broaching performance and increase lifespan.

A Coupling Response Surfaces Methodology of Multiple Constraints (CRSMMC) for parameters optimization of broach tool in broaching of heat-resistant steel X12CrMoWVNb N-10-1-1

Broaching fir-slots on the turbine discs is regarded as one of the key processes and the most difficult machining operations due to complex geometry and very tight tolerances. The heat-resistant steel X12CrMoWVNb N-10-1-1 is widely used as material in power-generation turbines. However, the manufacturability of the heat-resistant steel poses enormous challenges to the turbine plants. Subjected to several constraints including broaching force, broaching surface quality and broaching tool’s structure strength, machining efficiency, broaching tool’s life, and so on; the broaching process is mainly influenced by cutting speed, rake angle, clearance angle, and rise per tooth (RPT) of broach tool. A flexible evaluation method for multiple constraints, CRSMMC, is presented to acquire optimization parameters of broach tool for machining heat-resistant steel. Rake angle, clearance angle and rise per tooth (RPT) are designed as three factors by using the central composite design (CCD) method. In addition, broaching experiments of heat-resistant steel X12CrMoWVNb N-10-1-1 were performed in order to set up the model. In addition, the influences of broaches parameters on constraints were studied. The results indicated that the rise per tooth (RPT) was the dominant factor under the constraints of surface roughness and cutting force. Moreover, the predicted values obtained by CRSMMC were in good agreement with the experimental values, which indicated that CRSMMC was an effective method for broach tool’s parameters optimization in broaching of heat-resistant steel X12CrMoWVNb N-10-1-1.

Determination of Unit Cutting Force of GH4698 Broaching

Fir tree groove broaching is prone to deformation, which affects the machining precision of rear wheel groove. The numerical broaching force is calculated to improve deformation of the processed round tank .This paper uses the planer to make cutting tests that are carried out in shaping machine to simulate the wheel broaching process and measures the cutting force in the experiment. After analyzing the unit numerical cutting force of GH4698 broaching is finally obtained. It provides a simple method to calculate the cutting force of wheel groove machining.

Development of an in-house cutting forces simulation for fir tree broaching process

This article proposes a simulation of cutting forces in broaching of fir tree slots. Every step needed to build an in-house fir tree broaching simulation is presented. This simulation is based on the discretisation of each tooth of the broach, computation of elementary cutting forces of each discretised section, and finally the summation of each elementary cutting force into a global axes system. This work also presents orthogonal cutting experiments to implement realistic specific cutting forces into the model. The simulation obtained is compared with the real force signals of a fir tree broach to evaluate the quality of the simulation. At the end, the application to industrial context is developed.

Experimental Investigation on the Dynamic Cutting Forces in Internal Broaching

Cutting forces generated in broaching have a direct influence on the generation of heat, tool wear or failure, quality of machined surface and accuracy of the work piece. In this paper not only a cutting forces test scheme has been proposed but also a cutting forces measurement equipment has been designed with PCB 740B02 dynamical strain sensor and LMS SCADA III test system, respectively. Dynamical strain sensor was pasted on the cylinder type sensitive elements with which table and workpiece was connected. Experimental investigation on the dynamic cutting forces in the broaching direction of a hydraulic broaching machine had been carried out. Cutting forces measurement tests on Q235 steel workpiece material during broaching had been performed. Broaching in a variety of velocities, namely, 3.3m/min, 5m/min and 8m/min and in a variety of cutting depth, namely, 0.03mm, 0.04mm, 0.05mm and 0.07mm, were investigated. Output signal was analyzed both in time and frequency domains and the key characteristics of the cutting forces signal was obtained. Correlation between the frequency of broaching forces and the broaching velocity was also studied.

PM award winners show market diversity

The cutting forces in broaching, tapping or slotting seven steels with different compositions and microstructures were measured. The range of cutting speed was 1-15 m/min and three lubricants with various additive contents were used. The rheological and tribological properties of the materials were obtained from plane strain compression tests. A simple and original method is proposed to deduce the chip formation and evacuation, specific forces from the tool geometry, and the cutting force. The variations of these specific quantities with the machining process, the cutting speed, and the properties of the machined material are discussed.

A Comparative Analysis of three Machining Processes: Broaching, Tapping and Slotting

The cutting forces in broaching, tapping or slotting seven steels with different compositions and microstructures were measured. The range of cutting speed was 1-15 m/min and three lubricants with various additive contents were used. The rheological and tribological properties of the materials were obtained from plane strain compression tests. A simple and original method is proposed to deduce the chip formation and evacuation, specific forces from the tool geometry, and the cutting force. The variations of these specific quantities with the machining process, the cutting speed, and the properties of the machined material are discussed.