Based on the Merchant shear angle theory, two-dimensional high-speed orthogonal cutting experiments with an ‘OXCUT’ flow stress inverse procedure were used to determine the Johnson-Cook constitutive constants of the AISI 1045 steel (195HB). The constitutive constants obtained in the strain range 1.3-1.4 and large strain rate range 6106-7106/s. It is verified by experiments, and the result shows that the cutting forces are within the permissible error range. Compared the constitutive model with Hu’s, the cutting forces of this constitutive model of FEM are closer to the measurement, while the feed force has a relatively larger gap.
Studying the dynamic properties of a material are an important method to understand the dynamic processes and deformation mechanism of material at different working conditions, particularly at high strain rate. The constitutive equation of a material has the highest significance to represent the mechanical properties, and is the principal research basis for the numerical simulation. In this paper, an important titanium alloy TC11 was studied through the quasi-static tensile test and the split Hopkinson pressure bar (SHPB) tests. Dynamic compressive behavior of TC11 alloy was discussed. Moreover, this paper gave the constitutive model of TC11 alloy and established the Johnson-Cook (J-C) constitutive equation.
The stress-strain curves, mechanical behaviors, and Johnson-Cook model of 4Cr13 stainless steel were investigated at both the strain rates from 0.001s-1 to 7000s-1 and the temperatures from 293K to 673K based on the electronic universal testing machine and the split Hopkinson bar. The results showed that 4Cr13 stainless steel was very sensitive to the temperature and the strain rate. The temperature sensitivity factor decreased with increasing the temperature, and the strain rate sensitivity factor increased with increasing the strain rate. Both the temperature sensitivity factor and strain rate sensitivity factor decreased with increasing strain. The flow stress increased with strain rate and strain, but decreased with temperature. The J-C model prediction had a good agreement with the experimental stress-strain in the wide range of temperatures and strain rates. The Johnson-Cook model gave the foundation for finite element analysis during the cutting process.
In this study AISI 1045 steel of different hardness are used in high speed milling. According to Taguchi method, cutting parameters (milling speed, milling depth, feed per tooth) and workpiece hardness for the influence of high speed milling of the surface roughness are optimized. Through this study, not only the optimal cutting parameters of the minimum surface roughness is obtained, but also the main cutting parameters that effect performance in high speed milling is analysed. Researching results can be provided to guide establishment of the high speed milling process.
With the development of the coating technology, coated tools have been widely used in processing industries. Thread turning is one of its applications. The performance of coated thread inserts varies with the change of coating material, coating thickness, matrix material and tool structure. Two tungsten-cobalt type alloy matrix, TiAlN coated thread inserts with different coating thickness, rake face type had been employed to conduct the thread turning experiments. By analyzing the cutting forces, chip formation and tool wear, it was found that insert with coating thickness of 4.35 μm would result in less tool wear under MQL condition, smaller cutting force, better chip morphology under dry condition compared with insert with coating thickness of 2.38 μm.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.