THERMOVISION MEASUREMENTS OF THE TEMPERATURE IN THE CUTTING ZONE FOR TURNING AISI 321 STEEL

The article presents the methodology of conducting research on temperature distribution in the cutting zone for orthogonal turning without the use of a cooling liquid. AISI 321 austenitic steel was chosen as the workpiece material to be tested, while TNMA160408 carbide inserts, with a flat rake face made of H10F carbide, were chosen as the cutting edges. The research used infrared imaging, which still poses many research problems. The author's own method of calibration of the measurement chain is also presented. In addition, the most common causes of inaccuracies in thermovision measurements of cutting temperatures are discussed. The obtained temperature distribution maps were related to the average contact temperature determined by the method of natural thermocouple – chips/rake face.

The Temperature in the Cutting Zone when Applying Deformational Cutting to Form a Hardened Layer

Deformational cutting is a promising method of increasing wear resistance of friction surfaces by creating a strain hardened surface layer on them. An important factor influencing the deformational cutting process is the temperature in the cutting zone, therefore, it is necessary to obtain calculation formulas for predicting it. In this paper, the temperature change during deformational cutting of non-hardened austenitic steel in order to form a hardened layer was studied in relation to the cutting parameters: cutting depth, feed and cutting speed. Austenitic steel was selected as a promising material for strain hardening by the deformational cutting method. Temperature measurements were carried out using the natural thermocouple method. An empirical formula for calculating the temperature in the cutting zone depending on the cutting parameters was obtained.

Efficiency improvement for assigning of cutting conditions on the basis of the thermo-EMF signal

In the realities of modern machine-building production, control and management of processes occurring in the cutting zone are of great importance. The acquisition of control will significantly improve the stability and quality of processing, and the possibility of monitoring will help to increase the economic efficiency of production. This article presents the potential of the thermo-emf signal in a natural thermocouple “tool – workpiece” which is considered to be an information signal from the cutting zone. It also shows experimental proof of the influence between honing width on the front surface of the tool and its size.

Temperature measurement using natural thermocouple during grinding with monolayer grinding wheel

Presented is an example of temperature measurement during grinding of high-alloy steels with electroplated cBN grinding wheel. The grinding material and the nickel tape formed a natural thermocouple used for the measurements. A method for gaining the thermal characteristic of natural thermocouple was proposed.

Peculiarities in use of cutting- electromotive force signal under conditions of computer-aided machine manufacturing

In the paper there is considered a problem of properties heterogeneity in a terminal pair under conditions of computer-aided manufacturing. It is emphasized that this circumstance results in decrease of stability and quality of machining on the whole. The existence of tolerances for the content of chemical elements in steel is caused by a complexity in control of metallurgical processes. It is offered to use a parameter of thermo-electromotive force of a terminal pair “tool-blank” obtained in strictly definite modes of a calibrating cut for the further definition and optimization of cutting modes for machining. Drawbacks and possible variants for their solution at the realization of a method to measure cutting-electromotive force under production conditions are emphasized. A complex approach to the assessment of the influence of cutter geometrical parameters and technological factors of production upon the value of a thermo-electromotive force signal of a natural thermocouple “tool-part” is presented. It is established experimentally the influence of the antiwear coating state upon a thermo-electromotive force signal.

An Approximate Solution of Energy Partition in Grind-Hardening Process

In order to estimate the energy partition within the workpiece, an integral approximation solution of energy partition is found in the grind-hardening process. Heat transfer models of the abrasive grain, workpiece, chips and fluid were analyzed by using the integral approximation method. The present model can calculate the energy partition with and without film boiling in the grinding zone. The temperature underneath the surface of the workpiece was measured using semi--natural thermocouple method. The workpiece background temperature calculated by the present model agreed very well with the experimental results. Energy partition model can be used to calculate the grinding temperature for controlling thermal damage and predicting the harden layer depth in grinding.

Experimental Study on the Cutting Temperature Using Work-Tool Thermocouple while Machining TC4

The machining of titanium alloys classified as difficult machining materials. It is a major problem how to improve the machining efficiency of titanium alloys. The TC4 and YS8 natural thermocouple pair was calibrated and the variation of electromotive force with change of temperature was obtained. The calibrated results were used to measure the cutting temperature while machining TC4 and the variation regulation of cutting temperature with cutting speed was obtained.

Real-Time Monitoring System of Cutting Process Based on Cutting Temperature

Cutting temperature measurement and its variety tendency can reflect cutting tool performance and machined surface quality directly. By means of a mercury current collector or an electrical brush device the online measurement of thermoelectric potential of tool-workpiece natural thermocouple in milling is obtained, based on which a new cutting process real-time monitoring system is developed. The system takes the average cutting temperature in tool-workpiece interface as the monitoring target and the rotation rate of machine spindle as the adjustment object, which leaves out onerous and complex modeling and makes the monitoring and adjustment objective, direct and effective.