DEVELOPMENT OF SURFACE ROUGHNESS PREDICTION MODEL FOR HARD TURNING ON AISI D2 STEEL USING CUBIC BORON NITRIDE INSERT

2017 ◽  
Vol 80 (1) ◽  
Author(s):  
Amrifan Saladin Mohruni ◽  
Muhammad Yanis ◽  
Edwin Kurniawan

Hard turning is an alternative to traditional grinding in the manufacturing industry for hardened ferrous alloy material above 45 HRC. Hard turning has advantages such as lower equipment cost, shorter setup time, fewer process steps, greater part geometry flexibility and elimination of cutting fluid. In this study, the effect of cutting speed and feed rate on surface roughness in hard turning was experimentally investigated. AISI D2 steel workpiece (62 HRC) was machined with Cubic Boron Nitride (CBN) insert under dry machining. A 2k-factorial design with 4 centre points as an initial design of experiment (DOE) and a central composite design (CCD) as augmented design were used in developing the empirical mathematical models. They were employed for analysing the significant machining parameters. The results show that the surface roughness value decreased (smoother) with increasing cutting speed. In contrary, surface roughness value increased significantly when the feed rate increased. Optimum cutting speed and feed rate condition in this experiment was 105 m/min and 0.10 mm/rev respectively with surface roughness value was 0.267 µm. Further investigation revealed that the second order model is a valid surface roughness model, while the linear model cannot be used as a predicted model due to its lack of fit significance.

2015 ◽  
Vol 766-767 ◽  
pp. 649-654
Author(s):  
A. Srithar ◽  
K. Palanikumar ◽  
B. Durgaprasad

The machining of hard turning is performed on hardened steel in the range of 45 to 68 Rockwell hardness using a variety of tool materials such as Polycrystalline cubic boron nitride (PCBN) , Polycrystalline diamond (PCD) and Cubic boron nitride (CBN). It is an alternative to conventional grinding process is a flexible and effective machining process for hardened metals and hence broadly used in various applications such as dies, moulds, tools, gears, cams, shafts, axles, bearings and forgings. Although the process is performed within small depth of cut and feed rates, estimates to reduce machining time as high as 60 % in hard turning. This paper discusses the importance of hard turning of AISI D2 steel. In this study, Experimental investigations are carried out on conventional lathe using prefixed the cutting conditions. The responses studied in the investigation are cutting forces (Fa, Ft and Fz). The cutting parameters considered for the investigation are cutting speed, feed and depth of cut. The influence of machining parameters on response is studied and presented in detail.


2016 ◽  
Vol 686 ◽  
pp. 180-185 ◽  
Author(s):  
Marcel Kuruc ◽  
Martin Kusý ◽  
Vladimír Šimna ◽  
Jozef Peterka

Poly-crystalline cubic boron nitride (PCBN) is one of the hardest known material. Therefore only advanced methods are able to treat such material. Advanced machining methods, proper for machining of hard and brittle materials (such as glass and ceramics) include rotary ultrasonic machining (RUM). This method should achieve high precision and low surface roughness (at least during machining of materials such as ceramics). Achievable roughness is affected by machined material and machining parameters. This contribution investigates influence of machining parameters, such as cutting speed and feed rate, on resultant surface roughness during machining of PCBN by rotary ultrasonic machining.


2018 ◽  
Vol 142 ◽  
pp. 03002
Author(s):  
Yunhai Jia ◽  
Lixin Zhu

Ti-6Al-4V components are the most widely used titanium alloy products not only in the aerospace industry, but also for bio-medical applications. The machine-ability of titanium alloys is impaired by their high temperature chemical reactivity, low thermal conductivity and low modulus of elasticity. Polycrystalline cubic boron nitride represents a substitute tool material for turning titanium alloys due to its high hardness, wear resistance, thermal stability and hot red hardness. For determination of suitable cutting parameters in dry turning Ti-6AL-4V alloy by Polycrystalline cubic boron nitride cutting tools, the samples, 300mm in length and 100mm in diameter, were dry machined in a lathe. The turning suitable parameters, such as cutting speed, feed rate and cut depth were determined according to workpieces surface roughness and tools flank wear based on orthogonal experimental design. The experiment showed that the cutting speed in the range of 160~180 m/min, the feed rate is 0.15 mm/rev and the depth of cut is 0.20mm, ideal workpiece surface roughness and little cutting tools flank wear can be obtained.


2018 ◽  
Vol 20 ◽  
pp. 406-413 ◽  
Author(s):  
Ramanuj Kumar ◽  
Ashok Kumar Sahoo ◽  
Rabin Kumar Das ◽  
Amlana Panda ◽  
Purna Chandra Mishra

2018 ◽  
Vol 12 (1) ◽  
pp. 175-191 ◽  
Author(s):  
S. Yousefi ◽  
M. Zohoor

Objective: Hard turning in dry condition using cubic boron nitride tools, as an alternative of traditional grinding operation, is an advanced machining operation in which hardened steel with the hardness greater than 46 HRc is machined without the use of any coolant. Method: In the hard turning process, due to its hard nature, usually the cutting depth is selected lower than or equal to the nose radius, and the cutting zone is mainly limited within the tool nose area. Thus, unlike the traditional turning, the effect of the nose radius on the surface finish and dimensional accuracy becomes more complicated. Therefore, in this paper, firstly, the effect of processing parameters such as nose radius on the surface roughness and dimensional accuracy is investigated. Then, the relationship between the surface finish and dimensional accuracy variations with vibration, cutting forces, and tool wear is studied experimentally. The results revealed that feed rate is the most important factor influencing the surface roughness, whereas spindle speed and cutting depth are insignificant factors. On the other hand, cutting depth and spindle speed have the greatest effect on the dimensional accuracy, while nose radius has no significant effect. The vibration and wear analysis revealed that compared with the vibration, the tool wear has no considerable effect on the dimensional accuracy. It was also observed that the spindle speed has a contradictory effect on the surface roughness and dimensional accuracy. The best dimensional accuracy is obtained at 500 rpm, while the best surface quality is achieved at 2000 rpm. Result: The obtained results also showed that increasing the feed rate from a particular value not only leads to no significant changes in the surface roughness value but in some cases can also decrease the surface roughness. Conclusion: According to the analysis results, the lowest cutting depth, the moderate feed rate, and the speed lower than 1100 rpm provide the best dimensional accuracy. Compared with carbides and ceramics, cubic boron nitride tools produce a better surface roughness at both higher cutting depth and speed. 0.202 µm is the best surface roughness that was obtained at rε = 1.2 mm, N = 2000 rpm, f = 0.08 mm/rev, d = 0.5 mm which is comparable with the surface quality obtained by the conventional grinding operation.


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