Results – AdvisorAI

How to read these results. All values are model predictions with provisional coefficients. They show how the principles behave and how materials differ. They are not measurements. The ISO 8688-1 calibration programme is designed but not yet carried out. The case study uses the dissertation's speed and feed bands. The live tool uses each material's own database record, so its numbers can differ slightly.

Case study set-up

Part and tools

Test part with 22 operations and six tools. Results below are for the 50 mm, ten-insert carbide face mill (TiAlN, flood coolant), a_e = 35 mm.

Machine

Three-axis machining centre, 20 kW spindle, 75 % drive efficiency, spindle–holder stiffness 50 N/µm.

Materials

Ti-6Al-4V and Inconel 718 (S), AISI 304 (M), Al 6061-T6 (N), AISI 1045 (P), grey cast iron GG25 (K).

Different materials, different governing limits

On one machine with one cutter, four different physical limits decide the regime. A table of recommended values cannot show this.

Regimes selected by principle P1 (symmetric rule) and predicted process values
Material	v_c, m/min	f_z, mm	a_p, mm	F_c, N	Spindle load	T_cut, °C	θ	Tool life, min	Governing limit
Ti-6Al-4V	53	0.111	3.00	2 129	13 %	803	0.573	23.6	Machinability band
Inconel 718	20	0.084	2.23	2 365	5 %	661	0.610	> 240*	Thermal (enhanced cooling) and chatter
AISI 304	159	0.159	3.00	3 654	65 %	726	0.597	28.3	Machinability band
Al 6061-T6	300	0.265	3.00	2 068	69 %	291	0.660	106.9	Thermal (enhanced cooling)
AISI 1045	188	0.204	3.00	3 998	83 %	545	0.483	45.9	Spindle power
GG25	206	0.206	3.00	2 544	58 %	415	0.483	29.6	Machinability band

* Upper bound: the regime lies at the bottom of the speed band, where adhesion and notch wear, not described by the Taylor equation, dominate. θ = T_cut/T_solidus in kelvin.

Bar chart: three materials limited by the machinability band, one by spindle power, two by the thermal limit, one additionally by chatter. — Figure 1. Materials grouped by the limit that fixes the regime.

Stacked bars of primary and friction-zone temperature for six materials, and homologous temperature against the 0.45 and 0.60 thresholds. — Figure 2. Temperature split into shear-zone and friction-zone parts (left) and homologous temperature (right).

Depth first, then feed, then speed (rule P1-S)

Enumerating 11 × 11 × 11 regimes per material showed that the symmetric rule is either dominated or violates a requirement for five of six materials. The sequential rule reaches the Pareto front in every case that has an admissible regime.

Symmetric rule versus sequential rule P1-S (cutting time for the full part, tool life of the face mill)
Material	Symmetric v_c / f_z / a_p	Time, min	Life, min	Issue	P1-S v_c / f_z / a_p	Time, min	Life, min
Ti-6Al-4V	53 / 0.111 / 3.00	405	23.6	dominated by 90 regimes	43 / 0.150 / 4.00	279	30.0
AISI 304	159 / 0.159 / 3.00	95	28.3	dominated by 83 regimes	138 / 0.197 / 3.82	69	32.5
GG25	206 / 0.206 / 3.00	56	29.6	roughness above 1.6 µm	199 / 0.197 / 4.00	46	30.0
AISI 1045	188 / 0.204 / 3.00	62	45.9	roughness above 1.6 µm	180 / 0.150 / 4.00	66	66.1
Inconel 718	20 / 0.084 / 2.23	1 916	> 240	thermal limit exceeded	20 / 0.063 / 2.44	2 313	> 240
Al 6061-T6	No regime in the recommended band meets the single thermal threshold (see limitations)

Three scatter plots of admissible regimes with the Pareto front; the sequential regime lies on the front, the symmetric regime inside the cloud. — Figure 3. Admissible regimes (grey), Pareto front (red), symmetric regime (square) and P1-S regime (star). The advantage of P1-S survives doubling the feed and depth exponents of the Taylor equation.

Model behaviour

Taylor curves for six materials, and tool life against depth of cut for the corrected and the erroneous equation. — Figure 4. Corrected extended Taylor equation: tool life falls with depth of cut (centre). The earlier form made it rise (right).

Stacked bars of deflection for five milling tools; the 12 mm slot mill reaches 91 micrometres. — Figure 5. Tool deflection = spindle–holder compliance + tool bending. The slot mill comes closest to the 0.1 mm tolerance.

Engagement geometry

For a 50 mm, ten-insert cutter at a_e/D = 0.7, 3.16 teeth cut at once. A single-tooth force would understate spindle load 3.2-fold.

Temperature drivers

Predicted temperature depends mainly on specific cutting force and volumetric heat capacity. Thermal conductivity has a weaker effect.

Reproducibility

Every table and figure on this page is regenerated by the scripts in research/. See the documentation.