Modern Metals Machining Technology

Abstract

Titanium alloys such as A-110AT, B-120VCA, C-120AV, and 6-6-2AVT, which have been used to manufacture structural components for the aerospace industry, are difficult to machine when compared to aluminum and even some steel alloys. Tool wear for high-speed tool steel and carbide cutters takes place rapidly, necessitating the use of low cutting speeds and feeds to obtain a reasonable cutter life. In this study, the means used toward achieving an objective of increased producibility and reduced costs for titanium alloys was through an intensive machinability investigation of the machining characteristics. Control of pertinent machining variables, such as cutting speed, feed rate, tool material, tool geometry, machine tool setup, and cutting fluid, was rigorously maintained. Comparative cost analyses of the actual cutting operation and the attendant cutting tool costs were made concurrently with the study to obtain conditions which provided the best metal removal rate with reasonable cutter life at the lowest cost.

Machinability of Titanium Alloys in Drilling

“…Tool wear occurs due to the physical and chemical interaction between the cutting tool and workpiece as a result of the removal of small particles of the tool material from the edge of the cutting tool.Tool wear takes place in three stages as shown in Fig. 7 (Vaughn, 1966). Tool wear developed rapidly in the initial stage and then grew uniformly until it reached its limiting value.…”

“…Permissible rates of metal removal are low, in spite of the low cutting forces. The inhibitor in machining titanium alloys are the high temperature generated and the unfavorable temperature distribution in the cutting tool (Ezugwu & Wang, 1997;Vaughn, 1966 the low thermal conductivity of titanium alloys, the temperature on the rake face can be above 900º C even at moderate cutting speed.…”

“…Machining beyond this limit will cause catastrophic failures on the tool and usually this should be avoided. (Vaughn, 1966) The main problem in drilling titanium and its alloys is the rapid wear of the cutting tool. Permissible rates of metal removal are low, in spite of the low cutting forces.…”

High Efficient Mechanism of Material Removal in Two-Dimensional Ultrasonic Grinding from the Locus Perspective

“…How to obtain precise parts and how to improve the machining efficiency is of great interests to many scholars. Mechanical machining assisted by ultrasonic vibration is an effective method for hard-brittle materials, which has been presented in many articles [1,2]. In this paper, high effectiveness of material removal in ultrasonic grinding is analyzed from the aspect of grain locus, and the feasibility of grinding assisted by ultrasonic vibration for hard-brittle materials is confirmed.…”

Research on Prediction Model of Surface Roughness in Ultrasonic Polishing Nano-ZrO₂ Ceramics

“…Nano-ZrO 2 ceramics are promising materials for a large number of high-technology engineering applications due to their excellent properties such as high intensity, high strength and toughness and so on [1,2]. Generally, polishing is the finish process and polished surface is the final surface, so that the former plays an important role on properties of the latter.…”