Titanium Precision Forging: How To Control Process Defects?

Amid the wave of modern manufacturing transforming towards high-end and precision, precision forging technology, relying on its core characteristic of "near-net shaping", has become a key manufacturing technology in critical fields. By precisely controlling the plastic deformation of metals, it not only improves Titanium product performance and saves resource costs but also imposes stringent requirements on process management and control.

 

 

 

1. Precision and Surface Quality

The dimensional tolerance of precision forgings can be controlled within ±0.05~±0.2mm, and high-precision components such as aero-engine blades can reach ±0.02mm; the surface roughness Ra ≤ 1.6μm, and aluminum alloy parts can be as low as Ra 0.8μm, far exceeding traditional open die forging and ordinary die forging. Most of them only require a small amount of grinding to be used, greatly reducing subsequent cutting processes.

 

2. Outstanding Resource Utilization

Precision forging achieves near-net shaping, with a material utilization rate of 80%-95%; the single-piece material consumption of automotive transmission gears is reduced, and the material utilization rate of aero-engine blades is increased compared with casting, significantly reducing the waste of valuable alloys.

 

3. Optimized Mechanical Properties

Precision forging precisely controls metal flow, making grains uniformly refined along the stress direction and forming continuous and complete metal flow lines, avoiding the damage to grain structure caused by cutting. The fatigue strength of precision forgings is more than 20% higher than that of machined parts, and the service life is multiplied; the tensile strength and fatigue life of precision-forged engine crankshafts, as well as the high-temperature fatigue life of aerospace turbine disks, are improved, which can stably withstand extreme working conditions above 1200℃.

 

4.Significant Advantages in Production Efficiency and Cost Control

The single-piece cycle of automated precision forging production lines is only a few seconds to several minutes, with fewer subsequent processes and reduced comprehensive processing costs; although the initial investment in molds is relatively high, it saves materials and has a low scrap rate. For example, Nangong Jingqiang's high-efficiency temperature-controlled precision forging technology for connecting rods improves efficiency; precision forging can also achieve integrated forming, reducing assembly links.

 

 

1. Defect Occurrence and Raw Material Quality

Constructing a full-process defect control system requires source control and precise control of each link: raw materials are the foundation. The electric arc furnace + LF refining + VD vacuum degassing process is adopted to strictly control sulfur and phosphorus impurities, reduce the hydrogen content to within 2ppm, and use ultrasonic flaw detection to eliminate defects such as pores and inclusions, ensuring that the chemical composition fluctuation is ≤ ±0.02% and preventing forming problems caused by composition segregation.

2. Process Parameter Control

Temperature Control: Follow stepwise heating: slow heating at ≤100℃/h below 600℃, then heating to the target at 200-300℃/h; initial forging at 1150-1200℃ to prevent cracks, and final forging not lower than 850℃ to prevent white spots and uneven structure.

 

Cooling: Differentiated treatment according to cross-sections: air cooling for ≤100mm, furnace cooling at ≤50℃/h for >200mm, and pit cooling/sand cooling for special parts for ≥72 hours to prevent hydrogen-induced cracks.

 

Deformation Process: Forging ratio ≥5:1, multiple fireups of upsetting and drawing to eliminate looseness; rough forging deformation rate of 5-10%/min and precision forging <3%/min to reduce folds; multi-directional forging of special-shaped parts to ensure structural isotropy.

 

3. Mold and Equipment Status

Adopt high-precision insert molds, use resistance heating to match the mold preheating temperature with the forging temperature, and equip with a precise temperature control system with a temperature control accuracy of ±3℃; conduct regular inspections of molds, grind off small cracks in a timely manner and ensure the fillet ≥2mm, and repair the wear of flash grooves with electrical discharge machining to eliminate defects such as mold misalignment and galling.

 

Post-forging treatment and quality inspection are the final lines of defense: perform targeted heat treatment according to material characteristics, normalize after forging to refine grains to ASTM 6-7 grade, and add annealing for large forgings to eliminate stress; temper key parts to improve comprehensive mechanical properties, and assist with shot peening to strengthen surface compressive stress and extend fatigue life. Quality inspection requires ultrasonic flaw detection to check internal defects, metallographic analysis to verify grain size ≥5 grade, and strict testing of tensile strength, impact energy, etc., to ensure compliance.

 

 

Precision forging has laid a solid foundation for high-end manufacturing with its three high advantages. Defect control requires full-process management and control. In the future, it will develop towards intelligence, greenization, and ultra-precision, empowering the high-quality upgrading of industries such as aerospace and new energy vehicles.

 

Ruihang,as a professional manufacturer, is specialized in R&D,production and sales for titanium alloy products and precision components for industrial use. please contact us via email:Sam.Rui@bjrh-titanium.com