DD6

HuaNickel DD6 is a second-generation nickel-based single-crystal superalloy developed in China, which has the advantages of high temperature strength, good comprehensive performance, stable structure and good casting process performance. Compared with the second-generation single-crystal superalloys PWA1484, RenéN5 and CMSX-4 used abroad, its Tensile properties, durability, creep performance, oxidation resistance and hot corrosion resistance have reached or even partially exceeded its level, and it has the advantage of low cost because of its low Re content. The alloy has a durable strength of σ¹ ≥100 h, o ≥ 100 h, and is suitable for making high-temperature parts such as turbine working blades working below 1100°C and guide vanes working below 1150°C for gas turbines with complex inner cavities.

DD6Chemical composition：

	Ti	Cr	Co	W	Mo	AI	Nb	Ta	Re	Hf	Ti	Fe	B	Zr	Mn	Si	S
Min	Bal	3.8	8.5	7	1.5	5.2	0.6	6	1.6	0.05	≤
Max		4.8	9.5	9	2.5	6.2	1.2	8.5	2.4	0.15	0.1	0.2	0.02	0.1	0.15	0.2	0.001

DD6 Physical properties：

Density	8.78g/cm³
Melting point	1342℃~1399℃
Magnetic properties	not

Coefficient of linear expansion

θ/℃	20～300	20～400	20～500	20～600	20～700
α/(10-6℃-I)	11.92	12.59	12.93	13.15	13.53
θ/℃	20～800	20～900	20～1000	20～1100	20～1200
α/(10-6℃-I)	14.19	14.39	15.00	15.76	16.75

Resilient performance

θ/℃		25	650	700	760	850	980	1070	1100
E/GPa	[001]	131.5	107.5	107	105.5	98	80.5	69.5	67.5
	[011]	231.5	—	184.5	187.5	137.5	145	130	121
	[111]	327	—	212	184.5	205	217.5	189	176.5

DD6 Mechanical properties：

Standard number	Variety	sampling	Long-lasting performance			Tensile properties
			θ/℃	σ/MPa	τ/h	θ/℃	σb/MPa	σp0.2/MPa	δ₅/%	ψ/%
Q/6S 1678	Master alloy	[001]Monocrystalline test sticksStandard heat treatment	980	250	≥100	20	≥880	≥800	≥8	≥12
			1070	140	≥100	760	≥1000	≥850	≥5	≥6
			1100	130	≥100	980	≥700	≥600	≥18	≥22

DD6 Alloy properties：

HuaNickel DD6 is a second-generation nickel-based single-crystal superalloy, which has the advantages of high high temperature strength, good comprehensive performance, stable structure and good casting process performance.

DD6 Uses of alloys：

DD6 alloy has been selected for the fabrication of turbine working and guide vanes for a variety of advanced aero engines.

DD6 Process performance：

Parts Heat treatment: The blades with unprocessed surface should be treated with argon protection or vacuum, and then forced cooling by argon blowing, and the cooling rate should be greater than 260°C/min.

Relevant standards：

GB/T  14992 、Q/6S 1678