Effect of Process Parameters on Surface Roughness in Surface Grinding of 90CrSi Tool Steel

This paper aims to investigate the effect of process parameters on the surface roughness in suface grinding 90CrSi tool steel. In this paper, many process parameters including the coolant concentration, the coolant flow, the cross feed, the table speed and the depth of cut were taken into account. Based on conducting and analysing 25 experiments which were created by using full factorial design, the influence of the process parameters on the surface roughness was evaluated. Also, a predicted model to calculate the surface roughness was proposed.

Effects of Preheating Temperature at Primary Shear Zone in Laser Assisted Milling Process

In this paper, preheating temperature was investigated for the laser assisted machining (LAM) of Inconel 718 under different conditions for the milling test. The experimental results show that the requirement of laser power for the particularly preheating temperature proportionally increased with the table speed. The resultant cutting force for sufficient shearing work material in LAM was lower than conventional machining (CM) approximately 11, 21 and 28% for the cutting speed of 30, 50 and 75 m/min, respectively. The tool wear in LAM could be improved at relatively high cutting speed of 75 m/min and the hardness of machined surface in LAM was slightly higher than CM.

Performance of Water-Based Zinc Oxide Nanoparticle Coolant during Abrasive Grinding of Ductile Cast Iron

This paper presents the performance of ductile cast iron grinding machining using water-based zinc oxide nanoparticles as a coolant. The experimental data was utilized to develop the mathematical model for first- and second-order models. The second order gives worthy performance of the grinding. The results indicate that the optimum parameters for the grinding model are 20 m/min table speed and 42.43 μm depth of cut for single-pass grinding. For multiple-pass grinding, optimization is at a table speed equal to 35.11 m/min and a depth of cut equal to 29.78 μm. The model fit was adequate and acceptable for sustainable grinding using a 0.15% volume concentration of zinc oxide nanocoolant. This paper quantifies the impact of water-based ZnO nanoparticle coolant on the achieved surface quality. It is concluded that the surface quality is the most influenced by the depth of cut(s) and table speed.

Orthogonal Experimental Study on the Grinding-Hardened Layer’s Depth and its Uniformity of 45 Steel

Based on the orthogonal experiment of grinding-hardening machine, this paper studied the influence of depth of cut ap, table speed vw and grinding method gm on the grinding-hardened layer’s depth and its uniformity of 45 steel. The results show that, depth of cut ap is the significant factor affected the average value of grinding-hardened layer’s depth, but the influence of grinding conditions on the uniformity are very limited. In actual application, it should adopt ap=0.6mm, vw=0.4m/min and up-down grinding method to enhance the quality of grinding-hardened layer.

Study on the Two-Side Direction Burr in Grinding-Hardening Machine Based on Orthogonal Experimental Method

Based on the orthogonal experiment, this paper studied the influences of depth of cut ap, table speed vw and grinding method gm on the two-side direction burr in grinding-hardening machine. The results show that, with thermal-force coupling effect induced in the grinding-hardening machine, the metal in the workpiece’s surface flowed to two-side direction of the workpiece that without any constraint and leaded to the burr’s formation. The depth of cut ap and grinding method gm are significant factors that affected the size of two-side direction burr, and the significant order are as follows: depth of cut ap> grinding method gm > table speed vw>interaction av. With the increasing of depth of cut ap or the grinding trip, the max size of the two-side direction burr increased gradually; and with the raising of table speed vw, the max size decreased firstly and then increased. In actual application, it should adopted the grinding parameters ap＝0.2mm，vw＝0.6m/min and up-down grinding to improve the quality of grinding-hardening and reduce the size of the burr.

Quality and Control of Grinding-Hardening in Workpieces

On the basis of the surface grinding-hardening test, studied on the quality of grinding-hardening in 65Mn steel. The results show that grinding method has insignificant effect on the microstructure and the high hardness value of the completely hardened region at different locations alone the direction of length. The completely hardened region is composed of fine acicular martensites, residual austenites and a little carbides, and the high hardness value is between 760-820HV. As the changing of grinding method, the uniformity and depth of the hardened layer changed accordingly. The quality of grinding-hardening could be improved with big depth of cut, small table speed and combined with the grinding method of up-down grinding or down-up-down grinding which could effectively control the depth and uniformity of the hardened workpieces.

OPTIMALISASI PROSES GERINDA UNTUK PERMUKAAN

Basically, surface grinding is mechanical process that result high temperature and chemicalreaction on surface work piece. On this process, the heat energy has been released along ofthe surface. A part of the energy would be transferred to chip and the other would be continuedto the environment by grinder and work piece. Use of coolant on the surface of the object will befunction as lubricant, which can reduce friction between grinder and the object. Moreover, ingrinding process, cooling can effect on temperature and surface roughness. This research usedfactorial design 2x3x3 to evaluate the effect some variables process such as table speed, depthof cut also cooling method on temperature and surface roughness. High pressure air and air inroom temperature are kinds of cooling method in the process, the result of experiment would beanalysis by ANAVA. The experiment shows that temperature in air cooling method it is lowerthan by air of room temperature cooling method. The surface roughness of the work piece in aircooling method is the lowest. The faster table speed of grinding machine caused that the lowerof the grinding temperature and the work piece surface roughness. Moreover, the higher depthof cut would cause the higher grinding temperature and surface roughness.