DD402

HuaNickel DD402 is a nickel-based precipitation-hardening single-crystal superalloy, which is the first generation of single-crystal alloy. Compared with the first generation of foreign single crystal alloy PWA 1480 alloy, this alloy contains less tantalum, so the price is cheaper. The alloy has simple composition, low density, high creep strength and fatigue resistance, good single crystal casting performance, wide solution treatment temperature range, and good microstructure stability, environmental performance and coating properties. It is suitable for making turbine working blades and other high-temperature parts working below 1050°C.

DD402Chemical composition：

	Ni	Cr	Co	W	Mo	AI	Ti	Ta	Fe	Nb	Hf	B	Zr	Cu	Yb
Min	Bal	7	4.3	7.6	0.3	5.45	0.8	5.8	≤
Max		8	4.9	8.4	0.7	5.75	1.2	6.2	0.2	0.15	0.0075	0.003	0.0075	0.05	0.1

DD402 Physical properties：

Density	8.67g/cm³
Density	1330℃~1382℃
Magnetic properties	not

Coefficient of linear expansion

θ/℃	20～100	20～200	20～300	20～400	20～500
α/(10-6℃-1)	9.62	11.45	12.26	12.88	13.29
θ/℃	20～600	20～700	20～800	20～900	—
α/(10-6℃-‘)	13.66	14.08	14.58	15.23

Resilient performance

sampling	θ/℃	Ed/GPa	sampling	θ/℃	Ed/GPa
Monocrystalline test sticks	10	143	Monocrystalline test sticks	600	122
	100	140		700	118
	200	137		800	113
	300	133		900	108
	400	130		1000	105
	500	126		—	—

DD402Mechanical properties：

Standard number	Variety	sampling	Heat treatment	Tensile properties				Long-lasting performance
				θ/℃	σb/MPa	σp0.2/MPa	δ₅/%	θ/℃	σ/MPa	τ/h
GJB  5512.3、 HB 7762	Master alloy	Monocrystalline test sticks	standard Heat treatment	760	≥980	≥900	≥5.0	760	780	≥30
								980	260	≥30
Q/GYB 05047	Blade castings			760	≥980	≥900	≥5.0	760	780	≥30
								980	260	≥30

DD402Alloy properties：

The w(y’) phase in HuaNickel DD402 alloy is as high as 68%, and the average size of the γ’ phase is 0.45μm. Due to the small mismatch of γ/γ’, the creep strength of the alloy is high. The alloys not vanadium, low molybdenum, the right amount of tungsten and tantalum, and the optimal Ti/Al ratio guarantee the environmental performance and coating properties of the alloy. After the alloy is aged at 850°C × 3000h, the TCP phase does not precipitate.

DD402Uses of alloys：

DD402 alloy has been used in the manufacture of turbine working blades for advanced aero engines. The CMSX-2 alloy, which is similar to this alloy, has been successfully used in engines such as Arriel abroad.

DD402Process performance：

Surface treatment: The parts are sprayed with low-pressure plasma for multi-coating according to a special process.

Relevant standards：

GB/T14992 、GJB 5512.3  、HB 7762、HB7728、HB/Z140  Q/GYB05047