Here's a few things I found in a quick look. The first one deals with hydrogen embrittlement which Orenda were pioneers in solving. Titanium wasn't developed specifically for the arrow but Orenda were the first ones to design an engine around it. Avro doesn't get much credit, or mention for that matter, in other parts of the world because after it's cancellation, all the planes, records, blueprints and everything associated with it were ordered destroyed! Noted Canadian author Pierre Burton had said that the destruction of the completed airplanes was the biggest act of official vandalism in Canadian history. Avro were the recognized world leaders in high performance aircraft research and development in the 1950's. They had a passenger jet 7 years before Boeing! It has been said that without the cancellation of the Arrow, NASA wouldn't have put a man on the moon in 1969. One surviving Iroquois engine went to Bristol in the UK where they studied it's design to develop the engines for the Concorde. The chief of engineering at Avro was hired as a consultant on the Concorde.
"Shipments of mill products could not keep up with the demand of the jet engine builders and the airframe companies. Only 250 tons were shipped in 1952 and 1100 tons in 1953. Then metal in the shipments showed brittle failure further slowing production. The problem was hydrogen embrittlement, and was solved by annealing in a vacuum."
The Iroquois design was based on simplicity and lightness. With this in mind, Orenda pioneered work in the use of titanium in engines, with 20% by weight of the Iroquois (mainly the compressor rotor blades) consisting of this metal. Titanium has light weight, high strength and good temperature and corrosion resistance. It was estimated that the engine would be 850 pounds (386 kg) lighter than if steel had been used. During the early 1950s, this material was in short supply, and the lack of knowledge of its physical properties and fabrication techniques created problems which had to be overcome. It was also very expensive relative to the more common materials such as steel and aluminum.
It was recognized that if the engine parts could be designed with titanium, then the supporting structure could also be lightened due to reduced forces within the engine, with an overall saving in weight. Other parts, such as gearbox casings were made with a magnesium alloy. Inconel was used to make the blades in the low pressure turbine assembly and the metal insulation blanket found at the rear of the engine. This heat resistant nickel-chrome alloy retains its strength at high temperatures and resists oxidation and corrosion. The primary reason for using these advanced metals was to save weight and improve performance, creating an engine with a 5:1 thrust to weight ratio that could produce a sea level dry thrust of 19,250 lb (26,000 lb with afterburner). The design, development and manufacture of such an advanced jet engine was accomplished in an incredibly short time by the Orenda team. The detailed design was completed in May 1954, and the first run was achieved on 15 December 1954. The earlier Orenda 9 had more parts but produced less power. For example, the Orenda 9 weighed 2,560 lb (1,160 kg) and produced 6,355 lb (2,883 kg) static thrust, while the Iroquois weighed 5,900 lb. (2,675 kg) but was reported to have produced 30,000 lb (13,608 kg) static thrust with afterburner for takeoff. (The Orenda did not have an afterburner.)
The Iroquois was one of the most powerful jet engines in the world at its time of introduction, rated at 19,250 lbf (85.6 kN) dry, 25,000 lbf (111 kN) afterburning. It was aerodynamically matched for peak performance at 50,000 feet (15,200 m) altitude and Mach 2 speed.
