Cutting tool materials for high-speed machining For faster machining and higher productivity, which combination of properties must a cutting tool material possess to perform reliably at elevated temperatures and loads?

Introduction / Context:
High-speed and heavy-duty machining generate substantial heat and mechanical stress at the tool–chip interface. A modern cutting tool material must sustain its cutting edge without premature wear, softening, or chipping. This question reinforces the triad of essential properties for tool materials in metal cutting.

Given Data / Assumptions:

• Conventional single-point or multi-point cutting operations (turning, milling, drilling).
• Elevated cutting temperatures occur at the edge.
• Intermittent or continuous cuts may impose impact and cyclic loads.

Concept / Approach:
Three core properties govern tool performance: wear resistance (to slow flank/crater wear), red hardness (to retain hardness at high temperature), and toughness (to resist chipping in interrupted cuts or vibration). Lacking any of these leads to early failure or catastrophic edge breakdown.

Step-by-Step Solution:

Verification / Alternative check:
Tool families (HSS, carbides, cermets, ceramics, PCBN, PCD) are judged by these three attributes; selection charts always balance hot hardness versus toughness for the application.

Why Other Options Are Wrong:
Wear resistance only: tool may still soften or chip.Red hardness only: brittle edge may fracture; wear may be rapid.Toughness only: edge may wear quickly or lose hardness at temperature.Only high thermal conductivity: helpful for heat flow, but insufficient alone.

Common Pitfalls:
Choosing a very hard but brittle tool for interrupted cuts; or a very tough but low hot-hardness tool for high-speed finishing. Always match tool grade to operation and work material.

Final Answer:

All of these