Investigation of the Impact of Cutting Parameters on Surface Integrity in the End Milling of Inconel 625

Nickel based super alloys, such as Inconel 625 is amongst the most difficult to machine, due to its low thermal conductivity and high strength at higher temperature. Although, they are used in aerospace exhaust systems and other applications, the strain hardening that results during the machining operation, which adversely affects surface integrity of machined surface of such materials especially in extensive applications, is a cause for concern. In this context, this study was carried out, involving the milling operation, using solid carbide tools coated with TiAlSiN, under specifically developed conditions for dry machining of the difficult to cut materials. The cutting parameters were 4 in number, namely radial rake angle, feed per tooth, cutting speed and radial depth of cut and the response parameters included surface integrity characteristics, such as residual stresses, surface roughness and micro-hardness. Based on the experimental analyses, it was found that the micro-hardness of machined surface was higher. Micro hardness of sub surface decreases with the depth (50,100,150,250μm) due to a reduction in the work hardening of the Inconel 625, underneath the surface layer. The residual stresses were analyzed using main effect plot, and it was seen that the residual stresses were significantly influenced by the radial rake angle, followed by feed per tooth.

The effect of radial rake angle on chip thickness in the case of face milling

The existing models of undeformed chip thickness for face milling found in the literature neglect the radial rake angle of the tool, and they assume that its value is zero. The effect of the variation of the radial rake angle has not yet been discussed in the literature. As a novelty, this article investigates such an effect, especially the effect on chip thickness. A new tool model is proposed that takes into account the radial rake angle. A new method to calculate the chip thickness has been developed that uses the new tool model and is based on several existing numerical and approximation methods. It is analytically proved that the effect of the radial rake angle must be taken into account for calculating accurate results; however, in the case of lower feed rates, that effect is insignificant. The presented procedures are evaluated with respect to their accuracy and computing requirements. The proposed new methods have been verified by cutting experiments.

Influence of Wheel Position Parameters on Flute Profile of Micro-Drill

Drill flute has a great influence on the drilling performance of micro-drill, and its profile largely depends on the grinding parameters, wheel profile and position. It is promising to obtain a desired flute profile with a standard wheel by adjusting the wheel position parameters. To investigate the influence of wheel position parameters on the flute profile, the micro-drill flute is simulated by MATLAB software considering the wheel installation angle and the offset distance from wheel origin to the drill blank origin, and the radial rake angle, flute width and chip evacuation capacity are quantitatively calculated to evaluate the flute profile. The simulated results show that the wheel installation angle has an obvious effect on the three performance parameters of flute profile, and the wheel offset distance only influences a parameter, i.e., the flute width evidently. The radial rake angle of drill flute increases obviously with the increased wheel installation angle, and decreases slightly with the increased wheel offset distance. With the decreased wheel installation angle, the flute width of drill flute increases causing the reduction of micro-drill strength but improvement of the chip evacuation capacity. With the increased wheel offset distance, the flute width also increases resulting in the reduction of micro-drill strength but no obvious change on chip evacuation capacity. Thus the wheel installation angle can be used as a main factor among the wheel position parameters to obtain the desired flute profile.

Study on Plunge Milling Cutter Design with Finite Element Analysis

Plunge milling cutter withstanding greater loads in heavy milling can cause tool breakage, cutting vibration, even chatter. Firstly, geometric model of plunge milling cutter on various combinations of axial rake angle and radial rake angle are established. Secondly, with combination different axial rake angle and radial rake angle of plunge milling cutter under static load, the amount of deformation plunge milling cutter are calculated by finite element analysis. Finally, the plunge milling cutter first six natural frequencies are given in plunge milling cutter modal analysis with finite element analysis. The results show that minimum total deformation of plunge milling cutter is given with the axial rake angle 5° and radial rake angle-5 ° of the cutter and when the tool working at frequencies up to 10012HZ has caused vibration within the XY plane.

Wear of Milling Cutters in Machining of TC4 (Ti6Al4V) Titanium Alloys

Titanium alloys are difficult-to-cut materials, and the rapid wear of cutter is a big problem for machining of these alloys. In this paper, the wear characteristics of seven milling cutters in milling of TC4 (Ti6Al4V) titanium alloys are investigated. The results indicated that the averaged flank wear of each cutter linearly increases as the accumulated cutting length expands. Large radial rake angle as well as axial rake angle is favor for reducing cutter wear.

Visual Integrated Measurement on Geometry Parameters of Circular Saw Blade

Established the circular saw blade visual measurement system and developed geometry parameters measurement software. Calculated the inner and outer circle diameters and the roundness error, the tooth angle and the radial rake angle, the radial direction clearance angle on the basis of image processing. Calibrated the measured part using the standard gauge block. Improved the circle and the line sub-pixel methods. Experiment results showed that the fitting error of improved least–square linear fitting method was quarter of ordinary least–square linear fitting error under small difference of orientation time. The diameters of the inner circle and the outer circle ,the roundness error ,the tooth cusp angle and the radial rake angle, the radial direction clearance angle were respectively 25.204mm, 193.624mm, 0.005mm, 59.999°±0.00695°, 15.004°±0.0104°, 14.997°±0.0137° while taken sub-pixel method.