Multiple Quadratic Polynomial Regression Models and Quality Maps for Tensile Mechanical Properties and Quality Indices of Cast Aluminum Alloys according to Artificial Aging Heat Treatment Condition

Table 1

Mean values of the tensile mechanical properties and quality indices of cast aluminum alloy A357 according to 27 different artificial aging heat treatment conditions [2, 11].

	Aging temperature	Aging time	Yield strength	Tensile strength	Elongation at fracture	Strain energy density	Quality indices
	T(°C)	t(h)	YS (MPa)	UTS (MPa)	E f(%)	W(MJ/m^3)	Q(MPa)	Q R(MPa)	Q C(MPa)	Q 0(MPa)
1	155	6	160	277	19.52	49.38	470.5	1136.0	356.0	653.8
2	155	12	225	313	15.43	44.85	491.2	996.5	411.3	673.5
3	155	16	227	315	15.39	45.36	493.1	996.5	413.9	680.6
4	155	20	232	317	13.58	40.31	486.9	911.0	414.2	635.1
5	155	24	255	327	12.69	38.49	492.5	889.5	430.3	639.9
6	155	30	265	333	11.79	37.43	493.7	854.5	437.4	639.3
7	155	36	281	338	10.60	34.66	491.8	811.0	444.2	627.6
8	155	48	311	344	7.47	25.71	475.0	684.5	445.7	568.1
9	175	1	154	276	21.12	53.60	474.7	1210.0	354.4	690.0
10	175	3	190	292	17.68	48.36	479.1	1074.0	380.5	673.6
11	175	6	259	323	12.75	40.28	488.8	896.5	427.9	661.8
12	175	9	287	338	10.52	35.45	491.3	813.0	445.9	641.5
13	175	12	296	340	9.73	33.07	488.2	782.5	448.0	626.7
14	175	20	304	344	7.42	25.81	474.5	675.0	443.3	562.1
15	175	36	295	333	7.53	25.45	464.5	671.5	430.2	549.5
16	175	48	311	344	6.37	22.45	464.6	629.5	438.5	535.5
17	205	1	267	325	11.27	36.10	482.8	830.5	428.6	628.0
18	205	2	293	338	8.63	29.17	478.4	724.5	440.2	584.7
19	205	3	301	336	8.33	28.39	474.1	717.5	439.3	584.9
20	205	4	286	325	9.24	30.27	469.8	748.0	427.7	588.7
21	205	5	281	327	9.19	29.96	471.5	740.5	427.8	580.6
22	205	6	291	321	8.13	26.68	457.5	697.5	420.1	557.8
23	205	10	292	325	8.41	27.80	463.7	712.5	425.8	570.0
24	205	12	304	334	8.60	29.43	474.1	734.0	439.6	598.3
25	205	16	300	332	9.24	30.99	476.8	762.0	439.2	609.9
26	205	24	257	285	5.05	14.58	390.5	509.5	354.7	402.8
27	205	36	216	250	7.48	18.42	381.1	590.0	322.6	400.2